wip

3 files changed, 70 insertions, 2 deletions

diff --git a/main/i2c.c b/main/i2c.c
index 7ab1d14..3ecc2ee 100644
--- a/main/i2c.c
+++ b/main/i2c.c
@@ -8,7 +8,7 @@
 
 void init_i2c() {
     stdio_init_all();
-	i2c_init(i2c_default, 100 * 1000);
+	i2c_init(i2c_default, 100 * 1000); // currently at 100kHz
 
 	// Initialize I2C pins - sda(16), scl(17)
     gpio_set_function(SDA_PIN, GPIO_FUNC_I2C);
@@ -27,3 +27,63 @@ int write_i2c(uint8_t addr, uint8_t *input, size_t len) {
     // true to keep master control of bus
     return i2c_write_blocking (i2c_default, addr, input, len, true);
 }
+
+bool reserved_addr(uint8_t addr) {
+    return (addr & 0x78) == 0 || (addr & 0x78) == 0x78;
+}
+
+void init_addr_array(uint8_t array[]) {
+    for(int i = 0; i < MAX_SLAVES; i++){
+        array[i] = 0x00;
+    }
+}
+
+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
+        if( reserved_addr(addr) ){
+            ret = PICO_ERROR_GENERIC;
+        }else{
+            ret = i2c_read_blocking(i2c_default, addr, &rxdata, 1, false);
+        }
+
+        // if acknowledged -> ret == number of bytes sent
+        if(ret > 0){
+            array[i] = addr;
+            i++;
+        }
+    }
+
+    return array;
+}
+
+void bus_task() {
+    // scan bus for slaves
+    // send updates at regular intervals
+
+    int i = 0;
+    uint8_t *found[MAX_SLAVES];
+    init_addr_array(&found);
+
+    while(1) {
+        scan_bus(&found);
+
+        for(int i = 0; i < MAX_SLAVES; i++){
+            if( found[i] == 0x00 )
+                break;
+            
+            // send data to found slave address
+            write_i2c(found[i], 0x01, 1);
+
+            write_i2c(found[i], 0x00, 1);
+            // request update from slave addr at found[i]
+            //write_i2c();
+        }
+    }
+
+}
diff --git a/main/i2c.h b/main/i2c.h
index d12bca1..405ae1f 100644
--- a/main/i2c.h
+++ b/main/i2c.h
@@ -6,6 +6,7 @@
 
 #define SDA_PIN 16
 #define SCL_PIN 17
+#define MAX_SLAVES 10
 
 /**
  * \brief initialize all required gpio for i2c usage on the pico
@@ -28,9 +29,14 @@ int read_i2c(uint8_t addr, uint8_t *output, size_t len);
 
 /**
  * \brief write data to addr with length len from i2c bus.
- * 
+ * \param addr
+ * \param input
+ * \param len
  * This functions writes data to a specific address on the i2c bus,
  * the input var holds the data which will be written to the given 
  * address with length len.
  */
 int write_i2c(uint8_t addr, uint8_t *input, size_t len);
+
+/** \brief looking for slave addresses and requesting updates */
+void bus_task();
diff --git a/main/main.c b/main/main.c
index 73b6708..b38030f 100644
--- a/main/main.c
+++ b/main/main.c
@@ -7,6 +7,7 @@
 #include "config.h"
 #include "init.h"
 #include "sock.h"
+#include "i2c.h"
 
 void blink_task() {
 	await_init(); // `blink_task` uses GPIO
@@ -24,6 +25,7 @@ int main() {
 
 	xTaskCreate((TaskFunction_t) blink_task, "blink", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY + 2, NULL);
 	xTaskCreate((TaskFunction_t) serve_task, "serve", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY + 2, NULL);
+	xTaskCreate((TaskFunction_t) bus_task, "bus", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY + 2, NULL);
 
 	vTaskStartScheduler();
 }