Add on-power-on modem hook (before a reset was needed)

main.c

@@ -157,12 +157,9 @@ int main() {
  uart_setup(UART_A0, UART_BAUD_RATE_9600_SMCLK_12MHZ);
  uart_hub_select(1);
 
- PMCU_log("Syncing modem...");
+ PMCU_log("Syncing & resetting modem...");
  __pmcu_assert("modem", modem_sync());
 
- PMCU_log("Resetting modem...");
- __pmcu_assert("modem", modem_reset());
-
  PMCU_log("Attaching GPRS service to modem...");
  __pmcu_assert("modem", modem_gprs_attach());
 

modem.c

@@ -69,21 +69,21 @@ void modem_execute(const char *cmd) {
 }
 
 PMCU_Error modem_sync() {
- size_t i;
+ uint8_t tmp;
 
- uart_write(UART_A0, 27); // 27 = ESC key, if was sending something exits
+ /* Try to exit AT+CIPSEND state if was in */
+ uart_write(UART_A0, 27);
 
- for (i = MODEM_SYNC_RETRIALS; i > 0; i--) {
+ /* Wait until the modem is awake */
+ while (1) {
  modem_execute("AT");
- if (uart_read_until_string(UART_A0, "OK\r\n", NULL, NULL, 3) != PMCU_OK) { // delay of 3 seconds
+ if (uart_read_until_string(UART_A0, "OK\r\n", NULL, NULL, 3) != PMCU_OK) {
  continue;
  }
+ break;
  }
 
- return PMCU_OK;
-}
-
-PMCU_Error modem_reset() {
+ /* Reset modem to default state */
  modem_execute("ATZ");
  uart_read_until_string(UART_A0, "OK\r\n", NULL, NULL, MODEM_COMMAND_TIMEOUT);
 
@@ -103,6 +103,26 @@ PMCU_Error modem_reset() {
  return pmcu_error;
  }
 
+ /* Wait until find an available network */
+ while (1) {
+ __delay_cycles(12288000 * 3);
+ modem_execute("AT+CREG?");
+ if ((pmcu_error = modem_read(modem_buffer)) != PMCU_OK) {
+ continue;
+ }
+ tmp = strcmp(modem_buffer, "+CREG: 0,1") != 0 && strcmp(modem_buffer, "+CREG: 0,5") != 0;
+ if ((pmcu_error = modem_read_and_expect("OK")) != PMCU_OK) {
+ continue;
+ }
+ if (tmp) {
+ continue;
+ }
+ break;
+ }
+
+ /* Wait a few seconds to settle */
+ __delay_cycles(12288000 * 3);
+
  return PMCU_OK;
 }