gps: Found and fixed the issue about needing a double ON_OFF pulse

This was actually wrong, the Antenova M10478 GPS module doesn't need a double ON_OFF pin pulse, it just needs an ~150ms delay from the time its EXT_RST pin is asserted to the time it can dump out data. What was happening before is that we didn't have a delay in the gps_init function before sending the on_off pulse, and this meant that the pulse was missed by the module, which never turned on. The added delay fixes this issue and we now need only a single pulse.

gps: Found and fixed the issue about needing a double ON_OFF pulse
This was actually wrong, the Antenova M10478 GPS module doesn't need a double ON_OFF pin pulse, it just needs an ~150ms delay from the time its EXT_RST pin is asserted to the time it can dump out data. What was happening before is that we didn't have a delay in the gps_init function before sending the on_off pulse, and this meant that the pulse was missed by the module, which never turned on. The added delay fixes this issue and we now need only a single pulse.
ca039748 · Theodor-Adrian Stana · 24049003 · ca039748
Commit ca039748 authored Aug 22, 2014 by Theodor-Adrian Stana
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Showing with 8 additions and 24 deletions

main.c sw/gps/main.c +8 -24

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--- a/sw/gps/main.c
+++ b/sw/gps/main.c
@@ -80,23 +80,9 @@ int main()
        int i;

        for (;;) {
-                for (i = 0; i < 3000000; i++) {
-                        GPIO_PinInGet(gpioPortA, 1) ?
-                                GPIO_PinOutSet(gpioPortE, 11) :
-                                GPIO_PinOutClear(gpioPortE, 11);
-                }
-                usbdbg_puts("\r\nOFF\r\n");
-                gps_on_off_pulse();
-
-
-                for (i = 0; i < 3000000; i++) {
-                        GPIO_PinInGet(gpioPortA, 1) ?
-                                GPIO_PinOutSet(gpioPortE, 11) :
-                                GPIO_PinOutClear(gpioPortE, 11);
-                }
-                usbdbg_puts("\r\nON\r\n");
-                gps_on_off_pulse();
-
+                GPIO_PinInGet(gpioPortA, 1) ?
+                        GPIO_PinOutSet(gpioPortE, 11) :
+                        GPIO_PinOutClear(gpioPortE, 11);
        }

        return 0;
@@ -104,22 +90,19 @@ int main()

 static void gps_init()
 {
-        /* GPS reset pin */
+        int i;
+        /* Init GPS control pins & delay before ON_OFF pulse */
        USB->ROUTE &= ~(USB_ROUTE_VBUSENPEN);
        GPIO_PinModeSet(gpioPortF, 5, gpioModePushPull, 1);
-
-        /* GPS WAKUP pin */
        GPIO_PinModeSet(gpioPortA, 1, gpioModeInput, 0);
-
-        /* ON_OFF _double_ pulse */
        GPIO_PinModeSet(gpioPortE, 13, gpioModePushPull, 0);
-        gps_on_off_pulse();
+        for (i = 0; i < 100000000; i++)
+                ;
        gps_on_off_pulse();

        /* LEUART0 config */
        LEUART_Init_TypeDef init = LEUART_INIT_DEFAULT;

-        /* To avoid false start, configure output as high */
        GPIO_PinModeSet(gpioPortE, 14, gpioModePushPull, 1);
        GPIO_PinModeSet(gpioPortE, 15, gpioModeInput, 0);

@@ -151,6 +134,7 @@ static void gps_init()
 static void gps_on_off_pulse()
 {
        int i;
+
        /* Pulse */
        GPIO_PinOutSet(gpioPortE, 13);
        GPIO_PinOutSet(gpioPortE, 12);