rp2040 driver send still working (kinda)

3 files changed, 39 insertions, 29 deletions

diff --git a/lib/pbdrv/drv/rp2040/mod.c b/lib/pbdrv/drv/rp2040/mod.c
index 26882f7..b572c4e 100644
--- a/lib/pbdrv/drv/rp2040/mod.c
+++ b/lib/pbdrv/drv/rp2040/mod.c
@@ -11,12 +11,13 @@
 #define PBDRV_I2C i2c0
 #define BUF_SIZE 256
 
-// NOTE: this function is called from the I2C ISR, and should return as quickly
-// as possible.
+/**
+ * \note this function is called from the I2C ISR, and should return as quickly
+ * as possible.
+ */
 static void recv_event(i2c_inst_t *i2c, i2c_slave_event_t event) {
-	uint8_t data[BUF_SIZE];
-	size_t size = 0;
-	// pbdrv_i2c_recv(NULL, 0);
+	static uint8_t data[BUF_SIZE];
+	static size_t size = 0;
 
 	switch (event) {
 		case I2C_SLAVE_RECEIVE: {
@@ -39,6 +40,18 @@ void pbdrv_setup() {
 	i2c_slave_init(PBDRV_I2C, PBDRV_MOD_ADDR, &recv_event);
 }
 
+/**
+ * While the RP2040's datasheet claims it supports multi-master configurations
+ * by implementing bus arbitration, it does not natively support a mode where
+ * it is configured as a (multi-)master with a slave address, such that it can
+ * be addressed by other multi-masters. This function includes a hacky
+ * workaround that teporarily sets the RP2040 to I2C master mode to send a
+ * message, and then restores it back to slave mode.
+ *
+ * This approach results in some received frames being (partially) dropped in
+ * the time period between the invocation of this function and the bus becoming
+ * idle (and the message is sent).
+ */
 __weak void pbdrv_i2c_send(i2c_addr_t addr, const uint8_t * buf, size_t sz) {
 	i2c_set_slave_mode(PBDRV_I2C, false, PBDRV_MOD_ADDR);
 
diff --git a/main/i2c.c b/main/i2c.c
index 5db5b61..d92a93b 100644
--- a/main/i2c.c
+++ b/main/i2c.c
@@ -9,26 +9,26 @@
 #include "i2c.h"
 #include "pb-mod.h"
 
-uint8_t* scan_bus(uint8_t *array) {
-	int ret;
-	int i = 0;
-	uint8_t rxdata;
-
-	for(int addr = 0; addr < (1<<7); addr++) {
-		// ignore reserved addresses
-		// These are any addresses of the form 000 0xxx or 111 1xxx
-		// ret = i2c_read_blocking(I2C_PORT, addr, &rxdata, 1, false);
-
-		// if acknowledged -> ret == number of bytes sent
-		if(ret > 0){
-			printf("found i2c slave on addr: %d\n", addr);
-			array[i] = addr;
-			i++;
-		}
-	}
-
-	return array;
-}
+// uint8_t* scan_bus(uint8_t *array) {
+// 	int ret;
+// 	int i = 0;
+// 	uint8_t rxdata;
+// 
+// 	for(int addr = 0; addr < (1<<7); addr++) {
+// 		// ignore reserved addresses
+// 		// These are any addresses of the form 000 0xxx or 111 1xxx
+// 		// ret = i2c_read_blocking(I2C_PORT, addr, &rxdata, 1, false);
+// 
+// 		// if acknowledged -> ret == number of bytes sent
+// 		if(ret > 0){
+// 			printf("found i2c slave on addr: %d\n", addr);
+// 			array[i] = addr;
+// 			i++;
+// 		}
+// 	}
+// 
+// 	return array;
+// }
 
 void bus_task() {
 	// scan bus for slaves
@@ -40,7 +40,7 @@ void bus_task() {
 	// init_addr_array(found, MAX_SLAVES);
 	
 	while (true) {
-		vTaskDelay(9 / portTICK_PERIOD_MS);
+		vTaskDelay(10 / portTICK_PERIOD_MS);
 		pbdrv_i2c_send(0x69, (uint8_t *) "bbbbbbbb", 9);
 
 		// i2c_write_blocking(i2c0, 0x69, (uint8_t *) "bbbbbbbb", 9, false);
diff --git a/main/init.c b/main/init.c
index 1cfec9a..bd00c04 100644
--- a/main/init.c
+++ b/main/init.c
@@ -25,8 +25,6 @@ static void init_wifi() {
 	if (cyw43_arch_wifi_connect_timeout_ms(CFG_NET_SSID, CFG_NET_PASS, CFG_NET_AUTH, CFG_NET_CONN_TIMEOUT))
 		panic("cyw43_arch_wifi_connect failed\n");
 
-	printf("connected to Wi-Fi\n");
-
 	// TODO: announce hostname(?)
 }
 
@@ -35,7 +33,6 @@ static void init_i2c() {
 	gpio_set_function(CFG_SCL_PIN, GPIO_FUNC_I2C);
 
 	pbdrv_setup();
-	//printf("i2c setup\n");
 }
 
 static void async_init() {