When I send any commands to the HM10 BLE Bluetooth module, it sends the commands through bluetooth instead of the HM10 module processing the command. For example, I expected to send AT and have the module respond with "OK", but it sends the text "AT" through the bluetooth connection. I have tried sending the command with no bluetooth connection and the same thing happens. I have also tried sending the command via bluetooth instead of the serial connected to the device and I get the same thing.
When HM10 is connected to remote ble device it is in transparent mode. To put it into AT mode you need break connection or not establish it at all.
For breaking connection use reset/break pins. Reset is 12 pin and Break seems to be 23 pin.
It has sense to look IMME parameter of the module (page 32 of datasheet).
IMME Query/Set Module work type
1: When module is powered on, only respond the AT Command, don’t do
anything. Until AT + START, AT+CON, AT+CONNL commands is received.
0: When power on, module will start work immediately Default: 0
Also be carefull with strings endings, usually string doesn't need to be terminated with any symbol at all: AT, but some H11 need the string to end with CRLF: AT\r\n
Maybe (Maybe) your problem because of using clone module, try this solution with upload genuine firmware to your hm-10.
How to flash genuine HM-10 firmware on CC2541
I had problem close from your problem but for me no matter what I send I don't receive anything even to connected device, but after I upload that firmware, and change Module work mode to 1 (AT+MODE1) become able to send command even from connected device.
Related
I hit a deadened trying to receive sms on the SIM800L module with Arduino Uno.
I'm using the Receive sms sketch on the IDE, the module does not receive incoming messages and just keeps displaying one sms over and over, this message is the first one I sent to the module, and somehow it's stuck in memory. the sms.flush() method does't erase the message, how do I go about clearing memory to create space for incoming messages ? Thanks
The SIM800L has a vendor specific command to delete all messages, this may clear up enough space for it to receive additional messages.
Run AT+CMGDA=? to find out which mode you need to use. The modem responds with (1-6) or lists the responses in text mode.
Then run AT+CMGDA=6 if the modem responded with numbers, or AT+CMGDA="DEL ALL".
To avoid overflowing the storage, using AT+CNMI=2,2 you can tell the modem to always forward incoming messages to the terminal and avoid storing them in the SIM card or modem memory.
I am using ATEasy 7 142g in Windows 7.
I have a ZUP power supply module that I am communicating with RS232.
The weird thing is, that if I open HyperTerminal and send the device commands and try to receive result - all works fine.
BUT when I send the same commands in ATEasy and try to read results (and VERIFICATED it using the "monitor" feature), the zap module starts to send endless jibrish until I restart it (unplug it).
All the channel configurations are the same (baud rate etc...).
The set of commands that work in HyperTerminal but not in ATEasy:
:ADR01;
:RMT1;
:RMT?;
The result in case of HyperTerminal is :RM1;
In case of ATEasy the result is just jibrish until device restart.
What can be the reason?
In the end, the problem was entirly something else:
Noise from a motor cable was injected into the ZUP communication cable.
So everytime the motor was activated - the ZUP module com channel went crazy!
I'm working on an Arduino Uno + ESP8266 project.
I try to use them as a web server on Wi-Fi network to control a motor that connects to Arduino - basically a trigger system that receives signals via Wi-Fi. Currently, I've successfully connected ESP8266 to my access point by sending AT commands from Arduino. Another client on the same network can statically access ESP8266's assigned IP address.
However, when I try to catch some HTTP queries (I want to use them as conditions to control the motor) I occasionally encountered the non-ASCII characters in HTTP request. I use serial comm to debug, please look at the screenshot in the link below:
Arduino - Computer serial communication for debugging
The line ",519:POST ..." should contain a complete number following "/?", but there's some strange characters instead. So I cannot determine the input data to control motor. Once in a blue moon, the expected format of request shows up as follows:
The correct data received
There's no issue with the HTTP response part, even though I got the uninterpretable request, I can still send the JSON error message back to client.
Attempt Note:
The Arduino uses different serial ports to talk to computer and ESP8266. Since the connection can be established, and the data being sent, I believe that the baud rate is simply correct on both side. (115200 for ESP8266, 9600 for computer - also tried 115200 for both and got the same result)
I use V3.3 from Arduino as power source for ESP8266. But I also use voltage regulator to smooth out the current as many people suggest that. The problem still remains.
I'm struggled with this issue for a few days, just want to know if anybody had the similar experience, or could give some clue for the next step.
After a considerable effort to stabilize the circuit, I switched to NodeMCU and got the system working perfectly. I assume that ESP8266 alone is somehow not robust enough without other components, which I unfortunately have no knowledge on.
So I'd like to close this thread with a short recommendation for anybody struggling with the same issue to switch to NodeMCU (which would replace both Arduino and ESP8266); if that could support the requirement.
Just received my first ESP8266 wifi module with some excitement. However I've been unable to fully communicate with it. I have connected the module to my computer via a usb to serial cable and I'm power the module via a separate power supply (3.3v).
After powering the module up I receive the following information (via PuTTY or and Arduino serial monitor window):
[Vendor:www.ai-thinker.com Version:0.9.2.4]
ready
I have tried sending various AT commands e.g.
AT+RST
But I get no response. Using ctrl+m and ctrl+j in putty didn't help either.
Please see my youtube video if its helpful:
https://www.youtube.com/watch?v=RvasOuHuWDc
To get AT OK .
1.AT + PRESS ENTER + THEN CTRL +J WILL GIVE OK
2.Then Enter commands to execute
eg AT+GMR ->presss enter then ctrl+j
to get firmware
repeat step 1 for each command.
Make sure that you have putty or the Arduino serial console configured to send both a newline \n and a carriage return \r character. So AT+RST actually ends up being AT+RST\r\n. This took me a bit when I first received my ESP8266 modules. On the Arduino serial console this option is at the bottom of the window. I can see in your video you have it set to no line ending. Hopefully that does it for you.
I have an Arduino sending and receiving instructions with a Python script via a serial port.
The Arduino takes a button state and when it is pushed, it will send a message via the serial port to a Python script and await a response. (via Serial.available()). It works well enough.
However, if the Python script has crashed for whatever reason (ideally it will run in the background, so it can't be easily checked), the Arduino will wait forever and will be unavailable even on a script restart.
Is there a way for my Arduino to check if there is something listening on the serial port? (and alert me with flashing lights, etc. if not) or is this not how serial works? Worst case I guess I could use a timeout, although that is not ideal.
You have a limited ability to detect if there is something listening on the other side by using the DSR/DTR pins.
When you open the serial port on the machine your scripts runs on, it should raise its DTR pin (or you should be able to convince it to do so: the documentation of the library you use to drive the COM port should tell you how).
Then, on your Arduino, you can check its DSR pin (assuming null-modem wiring with handshaking, where the PC DTR pin is wired to DSR+CD on the Arduino) at regular intervals, and handle the 'nobody connected' scenario in any way you see fit.
One problem with this approach is that your PC script may not close the serial port when it crashes/stops responding, leaving the DTR pin enabled as if everything is still OK. Also, your script may simply miss the message from the Arduino due to errors on the serial line.
For that reason, you should always implement a timeout in your receive routines: even if there is a party listening at the other end, there is no guarantee it has received your message (or that its response will reach you intact).
Re-sending the message at least once (assuming DSR is raised) if a timeout occurs makes your protocol more reliable.
The Arduino doesn't use the DSR line or any other handshaking line, so you can't do what you suggest.
I agree with mdb that timeouts are necessary, but would also add that you might want to implement simple challenge/response system that periodically checks if anyone is listening. (I like ircd's Ping-Pong analogy).