wip

1 files changed, 61 insertions, 1 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();
+        }
+    }
+
+}