diff options
Diffstat (limited to 'docs/drivers')
-rw-r--r-- | docs/drivers/i2c.md | 124 | ||||
-rw-r--r-- | docs/drivers/spi.md | 8 | ||||
-rw-r--r-- | docs/drivers/uart.md | 26 |
3 files changed, 97 insertions, 61 deletions
diff --git a/docs/drivers/i2c.md b/docs/drivers/i2c.md index c806a090c5..ad74d0e481 100644 --- a/docs/drivers/i2c.md +++ b/docs/drivers/i2c.md @@ -16,17 +16,22 @@ You can then call the I2C API by including `i2c_master.h` in your code. ## I2C Addressing {#note-on-i2c-addresses} -All of the addresses expected by this driver should be pushed to the upper 7 bits of the address byte. Setting -the lower bit (indicating read/write) will be done by the respective functions. Almost all I2C addresses listed -on datasheets and the internet will be represented as 7 bits occupying the lower 7 bits and will need to be -shifted to the left (more significant) by one bit. This is easy to do via the bitwise shift operator `<< 1`. +I2C addresses listed on datasheets and the internet are usually represented as a 7-bit value. The eighth bit (the least significant bit) controls whether the operation is a read or a write. -You can either do this on each call to the functions below, or once in your definition of the address. For example, if your device has an address of `0x18`: +All of the address parameters expected by the driver API should therefore be pushed to the upper 7 bits of the address byte; the driver will take care of setting the read/write bit as appropriate. + +This is easy to do via the bitwise left shift operator. For example, if your device has an address of `0x18` you might create a define for convenience: ```c #define MY_I2C_ADDRESS (0x18 << 1) ``` +Or, you can shift the address ahead of time: + +```c +#define MY_I2C_ADDRESS 0x30 +``` + See https://www.robot-electronics.co.uk/i2c-tutorial for more information about I2C addressing and other technical details. ## AVR Configuration {#avr-configuration} @@ -39,12 +44,12 @@ The following defines can be used to configure the I2C master driver: No further setup is required - just connect the `SDA` and `SCL` pins of your I2C devices to the matching pins on the MCU: -|MCU |`SCL`|`SDA`| -|------------------|-----|-----| -|ATmega16/32U4 |`D0` |`D1` | -|AT90USB64/128 |`D0` |`D1` | -|ATmega32A |`C0` |`C1` | -|ATmega328/P |`C5` |`C4` | +|MCU |`SCL`|`SDA`| +|-------------|-----|-----| +|ATmega16/32U4|`D0` |`D1` | +|AT90USB64/128|`D0` |`D1` | +|ATmega32A |`C0` |`C1` | +|ATmega328/P |`C5` |`C4` | ::: tip The ATmega16/32U2 does not possess I2C functionality, and so cannot use this driver. @@ -52,7 +57,7 @@ The ATmega16/32U2 does not possess I2C functionality, and so cannot use this dri ## ChibiOS/ARM Configuration {#arm-configuration} -You'll need to determine which pins can be used for I2C -- a an example, STM32 parts generally have multiple I2C peripherals, labeled I2C1, I2C2, I2C3 etc. +You'll need to determine which pins can be used for I2C -- as an example, STM32 parts generally have multiple I2C peripherals, labeled I2C1, I2C2, I2C3 etc. To enable I2C, modify your board's `halconf.h` to enable I2C, then modify your board's `mcuconf.h` to enable the peripheral you've chosen: @@ -83,15 +88,19 @@ To enable I2C, modify your board's `halconf.h` to enable I2C, then modify your b Configuration-wise, you'll need to set up the peripheral as per your MCU's datasheet -- the defaults match the pins for a Proton-C, i.e. STM32F303. -|`config.h` Overrride |Description |Default| -|------------------------|--------------------------------------------------------------|-------| -|`I2C_DRIVER` |I2C peripheral to use - I2C1 -> `I2CD1`, I2C2 -> `I2CD2` etc. |`I2CD1`| -|`I2C1_SCL_PIN` |The pin definition for SCL |`B6` | -|`I2C1_SCL_PAL_MODE` |The alternate function mode for SCL |`4` | -|`I2C1_SDA_PIN` |The pin definition for SDA |`B7` | -|`I2C1_SDA_PAL_MODE` |The alternate function mode for SDA |`4` | +|`config.h` Override|Description |Default| +|-------------------|-------------------------------------------------------------|-------| +|`I2C_DRIVER` |I2C peripheral to use - I2C1 -> `I2CD1`, I2C2 -> `I2CD2` etc.|`I2CD1`| +|`I2C1_SCL_PIN` |The pin to use for SCL |`B6` | +|`I2C1_SCL_PAL_MODE`|The alternate function mode for SCL |`4` | +|`I2C1_SDA_PIN` |The pin to use for SDA |`B7` | +|`I2C1_SDA_PAL_MODE`|The alternate function mode for SDA |`4` | -The following configuration values depend on the specific MCU in use. +::: tip +Currently only a single I2C peripheral is supported, therefore the `I2C1_*` defines are used for configuration regardless of the selected peripheral. +::: + +The following configuration values are dependent on the ChibiOS I2C LLD, which is dictated by the microcontroller. ### I2Cv1 {#arm-configuration-i2cv1} @@ -147,7 +156,7 @@ void i2c_init(void) { --- -### `i2c_status_t i2c_transmit(uint8_t address, uint8_t *data, uint16_t length, uint16_t timeout)` {#api-i2c-transmit} +### `i2c_status_t i2c_transmit(uint8_t address, const uint8_t* data, uint16_t length, uint16_t timeout)` {#api-i2c-transmit} Send multiple bytes to the selected I2C device. @@ -155,10 +164,10 @@ Send multiple bytes to the selected I2C device. - `uint8_t address` The 7-bit I2C address of the device. - - `uint8_t *data` + - `const uint8_t* data` A pointer to the data to transmit. - `uint16_t length` - The number of bytes to write. Take care not to overrun the length of `data`. + The number of bytes to write. Take care not to overrun the length of `data`. - `uint16_t timeout` The time in milliseconds to wait for a response from the target device. @@ -168,6 +177,29 @@ Send multiple bytes to the selected I2C device. --- +### `i2c_status_t i2c_transmit_P(uint8_t address, const uint8_t* data, uint16_t length, uint16_t timeout)` {#api-i2c-transmit-p} + +Send multiple bytes from PROGMEM to the selected I2C device. + +On ARM devices, this function is simply an alias for `i2c_transmit(address, data, length, timeout)`. + +#### Arguments {#api-i2c-transmit-p-arguments} + + - `uint8_t address` + The 7-bit I2C address of the device. + - `const uint8_t* data` + A pointer to the data to transmit. + - `uint16_t length` + The number of bytes to write. Take care not to overrun the length of `data`. + - `uint16_t timeout` + The time in milliseconds to wait for a response from the target device. + +#### Return Value {#api-i2c-transmit-p-return} + +`I2C_STATUS_TIMEOUT` if the timeout period elapses, `I2C_STATUS_ERROR` if some other error occurs, otherwise `I2C_STATUS_SUCCESS`. + +--- + ### `i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout)` {#api-i2c-receive} Receive multiple bytes from the selected I2C device. @@ -176,10 +208,10 @@ Receive multiple bytes from the selected I2C device. - `uint8_t address` The 7-bit I2C address of the device. - - `uint8_t *data` - A pointer to the buffer to read into. + - `uint8_t* data` + A pointer to a buffer to read into. - `uint16_t length` - The number of bytes to read. Take care not to overrun the length of `data`. + The number of bytes to read. Take care not to overrun the length of `data`. - `uint16_t timeout` The time in milliseconds to wait for a response from the target device. @@ -189,9 +221,9 @@ Receive multiple bytes from the selected I2C device. --- -### `i2c_status_t i2c_write_register(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout)` {#api-i2c-write-register} +### `i2c_status_t i2c_write_register(uint8_t devaddr, uint8_t regaddr, const uint8_t* data, uint16_t length, uint16_t timeout)` {#api-i2c-write-register} -Writes to a register with an 8-bit address on the I2C device. +Write to a register with an 8-bit address on the I2C device. #### Arguments {#api-i2c-write-register-arguments} @@ -199,10 +231,10 @@ Writes to a register with an 8-bit address on the I2C device. The 7-bit I2C address of the device. - `uint8_t regaddr` The register address to write to. - - `uint8_t *data` + - `const uint8_t* data` A pointer to the data to transmit. - `uint16_t length` - The number of bytes to write. Take care not to overrun the length of `data`. + The number of bytes to write. Take care not to overrun the length of `data`. - `uint16_t timeout` The time in milliseconds to wait for a response from the target device. @@ -212,9 +244,9 @@ Writes to a register with an 8-bit address on the I2C device. --- -### `i2c_status_t i2c_write_register16(uint8_t devaddr, uint16_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout)` {#api-i2c-write-register16} +### `i2c_status_t i2c_write_register16(uint8_t devaddr, uint16_t regaddr, const uint8_t* data, uint16_t length, uint16_t timeout)` {#api-i2c-write-register16} -Writes to a register with a 16-bit address (big endian) on the I2C device. +Write to a register with a 16-bit address (big endian) on the I2C device. #### Arguments {#api-i2c-write-register16-arguments} @@ -222,10 +254,10 @@ Writes to a register with a 16-bit address (big endian) on the I2C device. The 7-bit I2C address of the device. - `uint16_t regaddr` The register address to write to. - - `uint8_t *data` + - `const uint8_t* data` A pointer to the data to transmit. - `uint16_t length` - The number of bytes to write. Take care not to overrun the length of `data`. + The number of bytes to write. Take care not to overrun the length of `data`. - `uint16_t timeout` The time in milliseconds to wait for a response from the target device. @@ -237,7 +269,7 @@ Writes to a register with a 16-bit address (big endian) on the I2C device. ### `i2c_status_t i2c_read_register(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout)` {#api-i2c-read-register} -Reads from a register with an 8-bit address on the I2C device. +Read from a register with an 8-bit address on the I2C device. #### Arguments {#api-i2c-read-register-arguments} @@ -245,8 +277,10 @@ Reads from a register with an 8-bit address on the I2C device. The 7-bit I2C address of the device. - `uint8_t regaddr` The register address to read from. + - `uint8_t data` + A pointer to a buffer to read into. - `uint16_t length` - The number of bytes to read. Take care not to overrun the length of `data`. + The number of bytes to read. Take care not to overrun the length of `data`. - `uint16_t timeout` The time in milliseconds to wait for a response from the target device. @@ -258,7 +292,7 @@ Reads from a register with an 8-bit address on the I2C device. ### `i2c_status_t i2c_read_register16(uint8_t devaddr, uint16_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout)` {#api-i2c-read-register16} -Reads from a register with a 16-bit address (big endian) on the I2C device. +Read from a register with a 16-bit address (big endian) on the I2C device. #### Arguments {#api-i2c-read-register16-arguments} @@ -266,8 +300,10 @@ Reads from a register with a 16-bit address (big endian) on the I2C device. The 7-bit I2C address of the device. - `uint16_t regaddr` The register address to read from. + - `uint8_t* data` + A pointer to a buffer to read into. - `uint16_t length` - The number of bytes to read. Take care not to overrun the length of `data`. + The number of bytes to read. Take care not to overrun the length of `data`. - `uint16_t timeout` The time in milliseconds to wait for a response from the target device. @@ -279,19 +315,19 @@ Reads from a register with a 16-bit address (big endian) on the I2C device. ### `i2c_status_t i2c_ping_address(uint8_t address, uint16_t timeout)` {#api-i2c-ping-address} -Pings the I2C bus for a specific address. +Ping the I2C bus for a specific address. -On ChibiOS a "best effort" attempt is made by reading a single byte from register 0 at the requested address. This should generally work except for I2C devices that do not not respond to a register 0 read request, which will result in a false negative result (unsucessful response to ping attempt). +On ChibiOS a "best effort" attempt is made by reading a single byte from register 0 at the given address. This should generally work except for I2C devices that do not not respond to a register 0 read request, which will result in a false negative result (unsuccessful response to ping attempt). -This function is weakly defined, meaning it can be overridden if necessary for your particular use case: +This function is weakly defined, meaning it can be overridden if necessary for your particular use case. -#### Arguments +#### Arguments {#api-i2c-ping-address-arguments} - `uint8_t address` - The 7-bit I2C address of the device (ie. without the read/write bit - this will be set automatically). + The 7-bit I2C address of the device. - `uint16_t timeout` The time in milliseconds to wait for a response from the target device. -#### Return Value +#### Return Value {#api-i2c-ping-address-return} `I2C_STATUS_TIMEOUT` if the timeout period elapses, `I2C_STATUS_ERROR` if some other error occurs, otherwise `I2C_STATUS_SUCCESS`. diff --git a/docs/drivers/spi.md b/docs/drivers/spi.md index 43d2a056d5..140b204945 100644 --- a/docs/drivers/spi.md +++ b/docs/drivers/spi.md @@ -88,7 +88,7 @@ Start an SPI transaction. #### Arguments {#api-spi-start-arguments} - `pin_t slavePin` - The QMK pin to assert as the slave select pin, eg. `B4`. + The GPIO pin connected to the desired device's `SS` line. - `bool lsbFirst` Determines the endianness of the transmission. If `true`, the least significant bit of each byte is sent first. - `uint8_t mode` @@ -106,7 +106,7 @@ Start an SPI transaction. #### Return Value {#api-spi-start-return} -`false` if the supplied parameters are invalid or the SPI peripheral is already in use, or `true`. +`true` if the operation was successful, otherwise `false` if the supplied parameters are invalid or the SPI peripheral is already in use. --- @@ -131,7 +131,7 @@ Read a byte from the selected SPI device. #### Return Value {#api-spi-read-return} -`SPI_STATUS_TIMEOUT` if the timeout period elapses, or the byte read from the device. +`SPI_STATUS_TIMEOUT` if the timeout period elapses, otherwise the byte read from the device. --- @@ -159,7 +159,7 @@ Receive multiple bytes from the selected SPI device. #### Arguments {#api-spi-receive-arguments} - `uint8_t *data` - A pointer to the buffer to read into. + A pointer to a buffer to read into. - `uint16_t length` The number of bytes to read. Take care not to overrun the length of `data`. diff --git a/docs/drivers/uart.md b/docs/drivers/uart.md index 7cc68727ee..b895266cab 100644 --- a/docs/drivers/uart.md +++ b/docs/drivers/uart.md @@ -45,17 +45,17 @@ To enable UART, modify your board's `mcuconf.h` to enable the peripheral you've Configuration-wise, you'll need to set up the peripheral as per your MCU's datasheet -- the defaults match the pins for a Proton-C, i.e. STM32F303. -| `config.h` override | Description | Default Value | -| --------------------------- | --------------------------------------------------------------- | ------------- | -| `#define UART_DRIVER` | USART peripheral to use - USART1 -> `SD1`, USART2 -> `SD2` etc. | `SD1` | -| `#define UART_TX_PIN` | The pin to use for TX | `A9` | -| `#define UART_TX_PAL_MODE` | The alternate function mode for TX | `7` | -| `#define UART_RX_PIN` | The pin to use for RX | `A10` | -| `#define UART_RX_PAL_MODE` | The alternate function mode for RX | `7` | -| `#define UART_CTS_PIN` | The pin to use for CTS | `A11` | -| `#define UART_CTS_PAL_MODE` | The alternate function mode for CTS | `7` | -| `#define UART_RTS_PIN` | The pin to use for RTS | `A12` | -| `#define UART_RTS_PAL_MODE` | The alternate function mode for RTS | `7` | +|`config.h` Override|Description |Default| +|-------------------|---------------------------------------------------------------|-------| +|`UART_DRIVER` |USART peripheral to use - USART1 -> `SD1`, USART2 -> `SD2` etc.|`SD1` | +|`UART_TX_PIN` |The pin to use for TX |`A9` | +|`UART_TX_PAL_MODE` |The alternate function mode for TX |`7` | +|`UART_RX_PIN` |The pin to use for RX |`A10` | +|`UART_RX_PAL_MODE` |The alternate function mode for RX |`7` | +|`UART_CTS_PIN` |The pin to use for CTS |`A11` | +|`UART_CTS_PAL_MODE`|The alternate function mode for CTS |`7` | +|`UART_RTS_PIN` |The pin to use for RTS |`A12` | +|`UART_RTS_PAL_MODE`|The alternate function mode for RTS |`7` | ## API {#api} @@ -111,7 +111,7 @@ Receive multiple bytes. #### Arguments {#api-uart-receive-arguments} - `uint8_t *data` - A pointer to the buffer to read into. + A pointer to a buffer to read into. - `uint16_t length` The number of bytes to read. Take care not to overrun the length of `data`. @@ -123,4 +123,4 @@ Return whether the receive buffer contains data. Call this function to determine #### Return Value {#api-uart-available-return} -`true` if the receive buffer length is non-zero. +`true` if there is data available to read. |