Hello,
I have an HC-05 with broken RX port (I burnt it while soldering... 
)
I want to control a GPIO port of the HC-05 via bluetooth (android). Is this possible?
Also, is there a way to "remap" the burnt RX port to a free GPIO?
Thank you.
ttouch:
Hello,I have an HC-05 with broken RX port (I burnt it while soldering...
I want to control a GPIO port of the HC-05 via bluetooth (android). Is this possible?
Also, is there a way to "remap" the burnt RX port to a free GPIO?Thank you.
If any of the above is possible, which is probably not the case, it needs to be weighed up against the fact the $7 will get you a new HC-05, probably complete with cable, thereby absolving you from any need to use an iron. If your dead HC-05 is on a JY-MCU backboard and this is actually where the damage has been done, you can get a new backboard for $1.83. This will involve soldering and daunting soldering at that, but I guess you are more experienced at that by now and it isn't that hard anyway.
If by GPIO you mean general purpose input output, you are assuming the HC-05 has several. I don't think it has any. It uses separate ports for input and output and has only one of each.
I mean the PIO pins and it has several.
It has AT command to control the (AT+PIO=,), but I don't know how to do it via bt.
I want to control a motor (on/off) via bluetooth. Isn't this possible with the HC-05?
It may be possible to use those pins but I believe they are solely for OEM use and every diagram I have seen says nearly all of them are not connected. But this is an Arduino forum and, if you connect an undamaged bluetooth module to one in the normal manner, you should be able to turn a motor on and off just fine.
Even the damaged would do the job this way, but I need a very small (I would really like a smaller module) and very low power solution.
Will the RN-42 do the job?
Yes, I believe it's the same as bluesmirf. The HM-10 is BLE and I understand there is a huge difference in power consumption.
Set the HC-05 in the AT mode and you may toggle the pins with the AT commands then.. Read the datasheet.
Can I send AT commands via bluetooth?
Nick, there is also a difference in the cost 
but if it's my only solution, I'll use it.
ttouch:
Can I send AT commands via bluetooth?Nick, there is also a difference in the cost
but if it's my only solution, I'll use it.
AT commands can only be sent from the serial port, not wirelessly via Bluetooth. To get the HC-05 into command state, the normal procedure I've seen and used myself is to tie one of the HC-05 pins to 3.3V and power it up. Having said that, it might be possible for the Arduino to control both the power to the HC-05 and the AT pin so it can switch modes when required.
The HC-05 will pull around 30ma in Bluetooth connected mode, down around 3ma in sleep mode (no Bluetooth connection). Probably best to power it via a transistor controlled by an Arduino pin.
One of the better documents for the HC-05 I found was this one:
For those PIO ports, I was briefly reading about that and what guys do is write their own firmware for the HC-05 to control PIO independently of the AT command mode.
Armed with all that, it may (or may not, I haven't tried it), be possible to send a command via Bluetooth to the Arduino, have the Arduino shut down the HC-05, power it up again in AT command mode, send the AT command to control the selected PIO pin, and after a certain amount of time, power cycle the HC-05 to return to normal mode. Pretty much a typical Arduino experiment.. 
As said, I don't want to use an Arduino and I may be wrong the topic here. If I use an Arduino, all my problems are gone, but the project is wearable, so low power and tiny size is a must.
ttouch:
Can I send AT commands via bluetooth?
No
Nick, there is also a difference in the cost
Yes, you are right. The difference is about 100%. Is it also $6.
I don't particularly recommend it but, if the low power is important, or if you want to use iStuff to control it, the $6 may be money well-spent. I also understand it has much greater range than the HC-05.
I was wondering if I could use the cc2540 chip that the HM-10 uses. It is tiny (hm-10 is kind of big), has ultra low power consuption and really really cheap (~1$ and I can order a couple of samples).
I will also buy the CC programmer (one time investment).
Will I be able to just program the chip and use it (by attatching an antenna) or I need super circuits to use it? (kind of redesigning hm-10)
My project is very simple. A bluetooth switch (ok, maybe a couple or so...). Send command and turn it off or on.
ttouch:
Will I be able to just program the chip and use it (by attatching an antenna) or I need super circuits to use it? (kind of redesigning hm-10)
I have no idea. Rather than "kind of" redesigning, it sounds like redesigning
My project is very simple. A bluetooth switch (ok, maybe a couple or so...). Send command and turn it off or on.
I'm afraid that, to me, simple is an HC-05 on a Mega. I don't know much about the HM-10. It's price suggests it could be the way of the future, but I'm not even sure about that.
Hi everyone!
Although this topic is belonged to long time ago, but I have the same problem today as I want to use a BT module which can be controlled directly via Bluetooth and works standalone.
It's about 5 years while this topic has been issued, but I couldn't find anything on the net which can propose a solution for controlling the HC-05 module PIOs via the Bluetooth. All people just recommend to use this module with Arduino.
I'm pretty confused while this module PIOs can be controlled in AT command mode, why the designer of the module hasn't considered any instruction for PIO controlling in normal mode by BT via the air.
does anyone has new comment?
I believe all your answers are in reply #8, and it also links to the best documentation.