From 137ed6702935b6c43d027dcd49fa52dc101f8e6e Mon Sep 17 00:00:00 2001
From: Laurent Meunier <laurent.meunier@st.com>
Date: Fri, 10 Aug 2018 10:15:47 +0200
Subject: [PATCH] Handle I2C scan with specific call to HAL_I2C_IsDeviceReady
When size is 0, the objective is to check if device is there and ready.
A typical use case is to scan through all addresses to check for
available slaves.
So we're checking the various error cases to report to application.
---
cores/arduino/stm32/twi.c | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/cores/arduino/stm32/twi.c b/cores/arduino/stm32/twi.c
index ccd633fb40..c715f46808 100644
--- a/cores/arduino/stm32/twi.c
+++ b/cores/arduino/stm32/twi.c
@@ -355,6 +355,11 @@ i2c_status_e i2c_master_write(i2c_t *obj, uint8_t dev_address,
uint32_t tickstart = HAL_GetTick();
uint32_t delta = 0;
+ /* When size is 0, this is usually an I2C scan / ping to check if device is there and ready */
+ if (size == 0) {
+ return i2c_IsDeviceReady(obj, dev_address, 1);
+ }
+
do{
if(HAL_I2C_Master_Transmit_IT(&(obj->handle), dev_address, data, size) == HAL_OK){
ret = I2C_OK;
@@ -447,8 +452,19 @@ i2c_status_e i2c_IsDeviceReady(i2c_t *obj, uint8_t devAddr, uint32_t trials)
{
i2c_status_e ret = HAL_OK;
- if(HAL_I2C_IsDeviceReady( &(obj->handle), devAddr, trials, I2C_TIMEOUT_TICK) != HAL_OK) {
- ret = I2C_BUSY;
+ switch (HAL_I2C_IsDeviceReady( &(obj->handle), devAddr, trials, I2C_TIMEOUT_TICK)) {
+ case HAL_OK:
+ ret = HAL_OK;
+ break;
+ case HAL_TIMEOUT:
+ ret = I2C_TIMEOUT;
+ break;
+ case HAL_BUSY:
+ ret = I2C_BUSY;
+ break;
+ default:
+ ret = I2C_TIMEOUT;
+ break;
}
return ret;