i try use BLE custom service with de API, but the propiertis for characteristics only accept CHR_PROPS_NOTIFY/CHR_PROPS_READ, I don’t know if with the new firmware the API can accept write characteristics or is it under development.
I need help,
thanks
Hello @and-tecnipak,
You are right. You cannot create a write characteristic with current firmware. You must change these two files to fix problem.
…/cores/apollo3/component/core/mcu/apollo3/uhal/uhal_cus.c
…/cores/apollo3/component/rui_v3_api/RAKBleUart.h
fixes.zip (5.6 KB)
You can add a write characteristic like below:
bslc.setProperties((RAK_CHARS_PROPERTIES) (RAK_CHR_PROPS_WRITE | RAK_CHR_PROPS_READ));
bslc.setPermission(RAK_SET_OPEN);
bslc.setFixedLen(1);
bslc.setWriteCallback(send_callback);
bslc.begin();
delay(1000);
uint8_t sensor_location = 2;
bslc.write(&sensor_location); // Set the characteristic to 'Wrist' (2)
Please be aware that these additions can cause problems. Testing is your responsibility. Also, I will inform R&D team to add this feature for next releases.
Best regards,
Sercan.
Hello Sercan,
Thanks for your response, can you explain me where’s this files to replace, I use de vscode for programming RAK, this files is a files for library of RAK11720 or how I will to replace this files?
For calling the write characteristic I use .setWriteCallback(send_callback);? Can you explain me with a example plis?
thanks, regards
Hello Andres,
Firstly, please install board support package according to this link: RAK11720 WisDuo LPWAN+BLE Module Quick Start Guide
After that, please check this link to find your Arduino15 folder.
You can find RAK11720 board support package inside “…/Arduino15/packages/rak_rui/hardware/apollo3/” folder.
At the end, you must change following files with my version (I shared previously.):
…/cores/apollo3/component/core/mcu/apollo3/uhal/uhal_cus.c
…/cores/apollo3/component/rui_v3_api/RAKBleUart.h
Again, the better way is to wait following RUI3 versions.
Please check custom service example to get more detailed information: BLE Custom Service | RAKwireless Documentation Center
Best regards,
Sercan.
Hello Serkan,
Thanks for your response, do you know when the new version for API RAK11720?
That version for API include write in characterictics BLE?
thanks.
Hi Sercan,
How can i receive the value what is written on my characteristic?
i don’t know how to use the send_callback() to receive the values and print to the serial monitor like in the example
can you explain me with an example?
Thanks
Currently, it is not added to latest RUI version. Please apply patches to be able to add write characteristic. Please take a look following example to learn how you can use write characteristic…
/***
*
* This example provide a BLE heart rate characteristic and callback function.
* While reading corresponding characteristic, the device will print message on console.
*
***/
#define UUID16_SVC_HEART_RATE 0x180D
#define UUID16_CHR_BODY_SENSOR_LOCATION 0x2A38
void send_callback(uint16_t chars_uuid, uint8_t * send_value)
{
if (chars_uuid == UUID16_CHR_BODY_SENSOR_LOCATION) {
Serial.println("[Heart Rate - Body Sensor Location Read or Write!]");
Serial.print("chars_uuid: ");
Serial.print("0x");
String uuid_str = String(chars_uuid, HEX);
Serial.println(uuid_str);
Serial.print("value: ");
char send_str[4];
sprintf(send_str, "%d", send_value[0]);
Serial.println(send_str);
Serial.println("");
}
}
void setup()
{
//Base 128-bit UUID : 0000180D-0000-1000-8000–00805f9b34fb
//--The 3rd and 4th byte '180D' means Service 16bit UUID
uint8_t base_uuid[] ={
0x00, 0x00, 0x18, 0x0D, 0x00, 0x00, 0x10, 0x00, 0x80, 0x00, 0x00,
0x80, 0x5f, 0x9b, 0x34, 0xfb};
Serial.begin(115200);
delay(2000);
Serial.println("RAKwireless BLE Custom Services Example");
Serial.println("------------------------------------------------------");
api.ble.custom.init();
RAKBleService hrms = RAKBleService(base_uuid);
RAKBleCharacteristic bslc = RAKBleCharacteristic(UUID16_CHR_BODY_SENSOR_LOCATION);
hrms.begin();
//Body Sensor Location
// 0 = Other
// 1 = Chest
// 2 = Wrist
// 3 = Finger
// 4 = Hand
// 5 = Ear Lobe
// 6 = Foot
// 7:255 = Reserved
bslc.setProperties((RAK_CHARS_PROPERTIES) (RAK_CHR_PROPS_WRITE | RAK_CHR_PROPS_READ));
bslc.setPermission(RAK_SET_OPEN);
bslc.setFixedLen(1);
bslc.setWriteCallback(send_callback);
bslc.begin();
delay(1000);
uint8_t sensor_location = 2;
bslc.write(&sensor_location); // Set the characteristic to 'Wrist' (2)
api.ble.custom.start();
}
void loop()
{
/* Destroy this busy loop and use timer to do what you want instead,
* so that the system thread can auto enter low power mode by api.system.lpm.set(1); */
api.system.scheduler.task.destroy();
}