Picaxe Editor and Bluetooth COM Port

fdxrate

New Member
I would like to be able to upgrade software on my project via Bluetooth, has anybody been able to access the Bluetooth COM port from within the Picaxe Editor and negated the need for a hardwire serial data link?
 

hippy

Technical Support
Staff member
Welcome to the PICAXE forum.

This being a duplicate post, and with no responses to the earlier (removed as duplicate), I would guess the answer is "no" or those who have got it working have not passed by the forum.

I cannot find any posts relating to successful download over Bluetooth. It is in theory possible but the Bluetooth link has to support 'break signalling', provide the required baud rate and have required signal polarity. There may also be issues with any delays caused while Bluetooth pairing takes place and the link is established when a port is opened for download.
 

fdxrate

New Member
Thanks Hippy, the BT device I am using is a common HC-06 which I have wired up to an un-programmed Picaxe chip, in this case an 08M2. Using a terminal program, I can send commands to the BT unit in the 'unpaired' state, and then when 'paired' to the Picaxe I can receive serial data from it. To the best of my knowledge, The BT unit is transparent to the process of sending and receiving serial data, merely acting as a conduit. Providing the baud rates are compatible, the serial data link can be established providing the software on the device wishing to establish the link to the Picaxe can see and then open the respective BT Port, (which is also listed in Device Manager).

Now, I can see the BT port in the Port list in my Terminal program and when I select it, I immediately open up serial communication, however, looking in my Picaxe Editor 'port list' I don't see the BT port listed. My question is, is there a definitive answer from RevEd giving a technical reason why its not listed or is it something else. Given that I can also pair the BT unit to my Samsung tablet via blutooth, open up an Android terminal app and immediately connect with the Picaxe chip, it would seem reasonable to assume that this level of connectivity would apply to the editor software as well. I'm sure there is a solution out there...
 

fdxrate

New Member
@Technical,
My project is controlled by smartphone app which is why I have Bluetooth installed. Eventually it will be sealed so cable connection to the Editor won't be possible. The units you are recommending, look like a USB/Serial adapter with wireless RF link, not Bluetooth.
 
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hippy

Technical Support
Staff member
Now, I can see the BT port in the Port list in my Terminal program and when I select it, I immediately open up serial communication, however, looking in my Picaxe Editor 'port list' I don't see the BT port listed. My question is, is there a definitive answer from RevEd giving a technical reason why its not listed or is it something else.
Similar anomalies have been identified before ...

http://www.picaxeforum.co.uk/showthread.php?20956-Bluetooth-to-com-port-problem

I don't recall we do have a definitive answer as to what the issue is. Our PICAXE software asks the OS what COM ports are available and shows what the OS returns. As noted in the above thread it is an issue which doesn't only affect PICAXE software.
 

srnet

Senior Member
The units you are recommending, (I didn't see datasheets at that site), look like a USB/Serial adapter with wireless RF link, not Bluetooth.
They are Wireless, and the remote programming works with these.

The datasheets should be found by clicking on the 'datasheets' tab below the picture.
 

hippy

Technical Support
Staff member
The units you are recommending, look like a USB/Serial adapter with wireless RF link, not Bluetooth.
That is correct; wireless RF, but not Bluetooth. This is our recommended means of wirelessly programming PICAXE chips.
 

SAborn

Senior Member
One thing i found with a "short " play with BT is there is a com port for TX and a com port for RX, not one com port for both as in serial.

This can cause problems with picaxe data via serial I/O, all good if you have the software installed to support this function, but not everything has it.

I doubt you will get BT to act a picaxe programming interface, so perhaps time to rethink your options before potting the project.
 

Technical

Technical Support
Staff member
The bluetooth serial protocol simply does not generally include the RS232 break feature. Or even setting DTR/RTS etc signals either. So bluetooth serial is nearly, but not quite, the same as 'real serial'. So you can do simple serial 'talking' back and forth ok, but not more advanced 'handshaking' type features.

Unfortunately this stops remote programming of a number of microcontroller products, including PICAXE.

The workaround is to the use the URF/ERF radio products instead. These have been specifically designed and modified to workaround these issues to support over-the-air programming.
 

Technical

Technical Support
Staff member
however, looking in my Picaxe Editor 'port list' I don't see the BT port listed. My question is, is there a definitive answer from RevEd giving a technical reason why its not listed or is it something else. Given that I can also pair the BT unit to my Samsung tablet via blutooth, open up an Android terminal app and immediately connect with the Picaxe chip, it would seem reasonable to assume that this level of connectivity would apply to the editor software as well. I'm sure there is a solution out there...
Which version of PE6 are you using - various bluetooth COM ports do show up ok on our machines and work for normal serin/serout style serial comms. You do indeed often get 2 virtual COM ports defined, but you should be able to use one of the two for successful talking in both directions.
 

geoff07

Senior Member
Can you enable any error-correction? They work nicely over very short range but over more than a metre or so they are too unreliable in my house, presumably due to too much gadget rf.
 

inglewoodpete

Senior Member
Can you enable any error-correction? They work nicely over very short range but over more than a metre or so they are too unreliable in my house, presumably due to too much gadget rf.
Error correction often needs to be applied at the upper levels of the OSI communications model, typically the Transport layer. In a PICAXE environment, you would need some form of checksum in each data packet. This can be quite crude while remaining quite reliable. On a checksum failure, some form of negative acknowledge (NAck) would be sent back to the other end, resulting in a retransmission.
 

geoff07

Senior Member
Indeed. But for downloads this has to be done by Rev-Ed or within the chipsets. Personally my only current interest is downloads, so I can update systems running in the house (mostly in the garage) without leaving my office!
 

BeanieBots

Moderator
I have had several attempts at PICAXE programming over bluetooth.
So far, all have failed even using units which claim to support the 'break' signal.

Bluetooth for serial comms works very with the cheap HC-05 / HC-06 devices.

For wireless PICAXE programming, the Rev-Ed customised ERF/URF simply work out of the box.
I have several projects which use both Bluetooth and ERF modules.
It does add a bit more cost but it is very reliable.
 
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