Bluetooth communication error for hex decimal

MIT App Inventor Help
1

Hello, I have a Bluetooth BLE 5 volt relay switch/not a arduino board. I am able to connect to device but get error. The communication error, device address not valid. just a need simple on/off switch to turn on light. The relay specifications say hexdecimal parameters:
A0 01 01 A2 RELAY ONE ON
A0 01 00 A1 RELAY ONE OFF

A0 02 01 A3 RELAY 2 ON
A0 02 00 A2 RELAY 2 OFF
Any help with the block or a sample code. Thanks

2

Search in this Community HM-10 and ESP32 BLE

1 Like
3

Thank you, I dont see anything but arduino, will this work for this device.

4

To send these hex sequences, you need to send them as unsigned byte lists.

Here are the equivalent decimal numbers for each byte:

  • A0 = 160
  • 02 = 2
  • 01 = 1
  • 00 = 0
  • A1 = 161
  • A2 = 162
  • A3 = 163

so

  • RELAY ONE ON = 160,1,1,162
  • RELAY ONE OFF = 160,1,0,161
  • RELAY TWO ON = 160,2,1,163
  • RELAY TWO OFF = 160,2,0,162
2 Likes
5

Here is a sample file that controls a single relay. It uses classic BT but in this case the code for BLE will not differ much. The commands (ON, OFF) can be Block Lists, as shown.

BT_RelaySwitch_01.aia (6.9 KB)

blocks
blocks863×3364 252 KB

Also attached is a version controlling eight relays:
BT_EDR_8_RelaySwitch.aia (12.7 KB)

1 Like
6

Thank you much, i will give that a try