I'm trying to finish a handmade custom board I started. I had previous problems with the crystals, and a few others, but right the thing seems to be working ok. At least I checked with UART that the board is running the hole code. I'm trying a simple Beacon example. But with the nRF Beacon application for Android I'm not seeing any signal. Even with the telephone touching the board. The board has a nRF51822FAAG0 with the balun BAL-NRF01D3, and a Johanson 2450AT43A100 chip antenna. I'm really lost here, I have a series of reasons in mind why the Bluetooth signal it's measing:
- A soldering problem with the balun. I had resolder the compoment a couple of times, I'm almost sure that it's in his right position, but it's very tricky to solder.
- The shunt capacitor of the antenna. I have a 1.5pF capacitor there, when the recommended it's 0.8pF. I'm trying to get the 0.8pF one.
- The 16Mhz crystal. I have this crystal with 18pF capacitors with 5% tolerance (the crystal load capacitance is CL = 12pF). The frecuency tolerance it's ok? Really don't sure because the datasheet it's not very clear.
- The design of the board and the code used it's from the OpenBeacon proyect. So, it's suppose to be a working proyect.
Can you help to understand where can be the problem? What can I try next? Thank you so much.
I leave here the schematics of the board, and a Photo of the proyect.
Update: And also the scope of the VDD_PA I got.
OpenBeacon.PDF OpenBeacon2.PDF
UPDATE: This is the code of my advertisment function.
static void radio_send_advertisment(void)
{
const TMapping *map;
int My_tasks_txen;
/* transmit beacon on all advertisment channels */
map = &g_advertisment[g_advertisment_index];
/* switch frequency & whitening */
NRF_RADIO->FREQUENCY = map->frequency;
NRF_RADIO->DATAWHITEIV = map->channel;
/* BLE header */
g_pkt_buffer[0] = 0x42;
/* add MAC address */
g_pkt_buffer[2] = (uint8_t)(g_uid>>24);
g_pkt_buffer[3] = (uint8_t)(g_uid>>16);
g_pkt_buffer[4] = (uint8_t)(g_uid>> 8);
g_pkt_buffer[5] = (uint8_t)(g_uid>> 0);
g_pkt_buffer[6] = 0;
g_pkt_buffer[7] = 0;
/* No BT/EDR - Tx only */
g_pkt_buffer[8] = 2;
g_pkt_buffer[9] = 0x01;
g_pkt_buffer[10]= 0x04;
/* append beacon packet */
g_pkt_buffer[1]= BLE_PREFIX_SIZE+g_beacon_pkt_len;
if(g_beacon_pkt_len)
memcpy(
&g_pkt_buffer[BLE_POSTFIX],
g_beacon_pkt,
g_beacon_pkt_len
);
/* set packet pointer */
NRF_RADIO->PACKETPTR = (uint32_t)&g_pkt_buffer;
NRF_RADIO->EVENTS_END = 0;
/* start tracker TX */
NRF_RADIO->TASKS_TXEN = 1;
My_tasks_txen = NRF_RADIO->TASKS_TXEN;
debug_printf("\n\rTasks_TXEN = %d\n\r", My_tasks_txen);
}
void POWER_CLOCK_IRQ_Handler(void)
{
/* always transmit proximity packet */
if(NRF_CLOCK->EVENTS_HFCLKSTARTED)
{
/* acknowledge event */
NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;
/* start advertising */
radio_send_advertisment();
}
}
