I update my esp8266-1 firmware sdk 1.5.0 AT version:0.51.0.0(Nov 27 2015 13:37:21).
Now I cant change my baud rate to 9600.
I tried AT+UART_DEF=9600,8,1,0,0 and AT+UART=9600,8,1,0,0 to change my baud rate. But after power off baud rate change to 115200. What can i do to save my default baud rate?
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I just connected an A6 GSM module and wrote a code to interact with it through the serial monitor connecting at 9600 baud rate. but the character "?" just keeps coming nonstop and nothing else works.
Here is my code:
#include<SoftwareSerial.h>
SoftwareSerial gprs(8, 9);
void setup(){
gprs.begin(9600);
Serial.begin(9600);
}
void loop(){
while (gprs.available())
Serial.write(gprs.read());
while (Serial.available())
gprs.write(Serial.read());
}
I later found you should connect it at 115200 baud rate, and if you want to change the baud rate, command it to do so while you are on default baud rate.
AT+IPR=9600 -- to change it
AT&W -- to save the change
and lowering the baud rate is crucial if using software serial.
(the second command should be sent after reconnecting at 9600, since the first command changes the baud rate)
I've connected my SIM900a module with PC by using a TTL converter. I've tried two or three terminal (including putty and TMFT) to communicate with this module. But none of them are working. I can't even write anything on these terminal! What am I doing wrong here?
Connect your PC's TX pin to RX pin of SIM900A and PC's RX pin to TX pin of SIM900A.
You also need to connect your TTL converter's power supply to VMCU pin. This is generally the voltage level of your UART TX & RX pins.
You may also needs to ground the PWRKEY for a second or two to turn the module on.
Serial Port Settings :
Baud Rate : 9600
No. of Bits : 8
No. of Stop Bits : 1
Soft-Flow Control : None
Hard-Flow Control : None
If baud rate of 9600 doesn't work you cal also try a baud rate of 115200.
Don't forget to include carriage return character at end of each command.
e.g.
const char *at_test = "AT\r"
UPDATE:
I figured the problem was with the connection over the PL2303. I reduced the BAUD rate of ESP to 9600 bps with help of an Arduino. Contacted the manufacturer of PL2303 and will update the post with the instructions when I receive them.
I'm trying to get an ESP-201 (variant of ESP8255) to work on Windows host. My aim is to configure the setup correctly and valitade by geting an OK response for AT command.
I've read that PL2303 PC-side default baud rate is 9600 and ESP-201's baud rate is 115200. I've suspected that data I'm sending isn't received correctly by ESP so I tried to configure the BAUD rates. I tried do it with Python because PuTTY connects to the device but doesn't let me give any input to the terminal. So I've tried to run this Python code, without the ESP connected to the PL2303.
import serial
esp = serial.Serial(port="COM5", baudrate=9600, timeout=1)
esp.write(b"PLBAUD 115200")
time.sleep(500)
print(esp.readline())
esp.write(b"BAUD 115200")
time.sleep(500)
print(esp.readline())
This should first set the ESP side BAUD rate of PL2303 to 115200 then set the PC side BAUD rate to 115200. But sending the AT command with the following code doesn't yield the expected OK response after changing BAUD rate setting in Windows device manager BAUD settings and plugging in the ESP module.
import serial
esp = serial.Serial(port="COM5", baudrate=115200, timeout=1)
esp.write(b"AT\r\n")
print(esp.readline())
Incase the strings sent are in UTF-8, I encoded them to hex manually and sent them again and result didn't change.
I've contacted Waveshare, maker of this module, and learned that the host PC and the device on the TTL side of this adapter must have the same BAUD rate in order to work. Set them both back to 115200 and it is solved.
This is due to the adapter not having a buffer that adapts the BAUD rate, rather than it being a pass-through device.
I get strange encoded messages from my sim900 module when I enter AT commands. I have set the baud rate to 9600. I've tried using several terminals but to no avail.
Any help is appreciated.
Thanks
I am quite sure the issue is with baud rates. Your terminal baud rate should be set to the baud rate of the module. There can be one of the followings issues with your setup
Your sim900 module is set to another baud rate (try 115200)
You are not sending \r at the end of your commands
Your sim900 is in auto-baud state and is waiting for AT\r command to lock in to the baud rate you are communicating in. In this state you need to send AT in uppercase a few times after the modem switches ON.
Problem: How to access a device whose baud rate is 921600 from Windows 7 PC.
I have an embedded device and I used to connect to this device through USB Serial Port at a baud rate of 115200.
Now, the embedded device's baud rate is changed to 921600. I cannot communicate with this device.
I have a terminal program (Teraterm) in which I can set the baud rate to 921600. But I am not able to communicate with the emb device as the maximum baud rate that can be set in Windows 7 device manager for this device is 128000.
I even tried with a Python script (changing baud rate 921600) which was working earlier (at baud rate 115200). Now it's not working.