Sim800 Evb Kit Schematic
SIM800 SeriesSTKApplication NoteV1.00. Document Title. Figure 2: Basic AT command flow block diagram. Set up idle mode text. May 24, 2019 - 4.1 Schematic; 4.2 SIM800 Board Series Details; 4.3 SIM808 Board Series Details. 7.1 SIM800-Mini; 7.2 SIM800C-Full Board R1-old; 7.3 SIM900; 7.4 Schematic. SIM908 EVB Schematics, SIM908, HD-design file, -. SIM800 - SIMCOM - Download PCB Footprint & Schematic Symbol. Product - SIM800 EVB KIT SIM800 EVB KIT. More details on CREG can be found in.
Power supply
You cannot power the module from the Arduino, as it is incapable of supplying the necessary peak currents. The Sim900 draws about 2A every so often. It's not necessary to build a 2A supply, as a large storage capacitor on the power supply output will supply the current. I am using a small switch mode buck power supply to step down from an external 12V DC source to 3.3V, with a 0.1F 5V super capacitor on its output and that works a treat. I believe that a 1000uF low esr cap will also work, but I've not tried it. The photo shows the power supply with a 0.1F cap underneath.
Serial port
True code for renault 3.2 7. The Sim900 communicates at TTL levels limited by its power supply voltage. The hardware reference manual says TXD and RXD (serial transmit and receive respectively for the Sim900) max output and input voltage respectively is the same as the power supply..3.3V in my case.
The Arduino UNO, when using the SoftwareSerial library, transmits data on its digital IO pins at their voltage levels. When the Uno is supplied at 5V the maximum output voltage is 4.2V, and is 2.3V when supplied by 3V.
Sim800l Evb Arduino Uno
At first I put a voltage divider into the transmit signal path, but found it was not necessary, and it works to transmit and receive serial data between the module and the Uno.
Sim800 Evb Kit Schematic Chart
Wiring it up
You will need to work out which digital pins are used by your preferred library provider for their compatible GSM shield. In my case I will use digital pins 2 & 3 and SoftwareSerial on the UNO. Some also use another digital pin to control switching power on and off for the GSM shield. Connect the UNO TX SoftwareSerial pin to the mini module RX pin and similarly for the Uno RX pin. Remember to connect common grounds between the UNO and the power supplies and the mini module.
Do NOT use the RS232 outputs on the side of the PC board, as it outputs some +-7V and can damage your Arduino. The TTL level serial output pins must be used (near the antenna connection). Also please check the ground pins on the connector as some people have reported that the pinout of their module is different to that shown in the photos of my mini module.