This device is capable of generating square wave signal for experimental development that involves PWM dimming and speed controlling (e.g. motor drivers) as well as other micro controller use. It can be controlled via the Serial Protocol TTL (TXD & RXD pins). It is stable and reliable, and fairly simple to use.
This signal generator is based on a 16MHz, 8-Bit MCU STM8S003F3, and a Holtek HT1621B LC display driver, 4 buttons control frequency and duty cycle. It can also be remote controlled by the serial port (see info below).
Operating Voltage: 3.3 – 30 VDC**
Frequency Range: 1Hz ? 150 KHz
Frequency Accuracy: the accuracy in each range is about 2%
Signal Load Capacity: 5 – 30 mA
Output Amplitude: PWM Amplitude Equal to the Supply Voltage
Operating Temperature: -20 – +70 Celsius
Dimensions: 52 x 32 x 10 mm
9600 bps Data bits: 8
Stop bit: 1
Check digit: none
Flow control: none
1) Setting the frequency of the PWM:
Command “F101”: Set the frequency to 101 HZ (001 to 999)
Command “F1.05”: set the frequency of 1.05 KHZ (1.00 ~ 9.99)
Command “F10.5”: Set the frequency to 10.5KHZ (10.0 ~ 99.9)
Command “F1.0.5″: set the frequency of 105KHZ (1.0.0 ~ 1.5.0)
2) Setting the PWM duty cycle:
DXXX”: set the PWM duty cycle to XXX; (001 ~ 100)
Example: ?D050?, sets the PWM duty cycle is 50%
3) Read the set parameter
Send a “read” string to read the set parameters.
Set successfully return: DOWN.
Setup failed to return: FALL.
**NOTE: Since we can’t confirm the exact type of the LDO voltage regulator on board, we recommend not to operate this device on a voltage of more than 15V DC (we recommend 4V to 15V).