Hardware Recommendation for a MSDroid newb

[Dozer2FEYota]

Can anyone make a quick recommendation for a tablet that works really well for this application as well as the bluetooth adapter. I am running MS2. I'm an Apple guy, so completely new to all of this, but fairly technical. Cost, as always, is a concern - however, I want something that will work fairly well out of the box and am willing to spend a little more for ease of use.

TIA.

[ol boy]

As for tablets... any one running android of course with a built in bluetooth (BT). I found last year that the really cheap tablets out there don't have BT built in. I'd look for a samsung xxxx tab xx type. Pick which ever size you want. I really like the 5.0 player that was out 4 years ago, but never bought one. Now some android based smart phone has screens bigger than 5 inch.

As for BT to serial/UART widgets... I'm currently having good luck with RN-41XV stuff which is at UART level (0 to 3.3 volts). It's default baud rate is 115200 so that remove the headache of screwing with the inners of the BT module in command mode. The RN-41 is a class 1(good to 300ft), the RN-42 is the same hardware but is a class 2 power output. Class 2 is good for 75ish feet. Most phones/tablets are class 2 BT so even with a class 1 in your ECU the phone can only transmit data up to 75ish feet.

Depending on your skills you can build a small proto board that will hold you BT module and a 3.3v regulator. Connect the rx line to the tx line from the MS2 processor side of the RS232 chip. Then the tx to the rx line from the MS2 processor side of the RS232 chip. I did notice after doing this I could no longer get good data transfer over serial cable as the processor side of the RS232 chip could not drive the UART lines low enough to get a logic 1. One option is to wire up a switch or series of dip switches to disconnect the BT UART line from the RS232 UART lines for when you need to hook a hard line from the laptop to the MS box.

The easy option is to just buy that BT to serial widget from Phil.

[racingmini_mtl]

As for tablets... any one running android of course with a built in bluetooth (BT). I found last year that the really cheap tablets out there don't have BT built in. I'd look for a samsung xxxx tab xx type. Pick which ever size you want. I really like the 5.0 player that was out 4 years ago, but never bought one. Now some android based smart phone has screens bigger than 5 inch.

As for BT to serial/UART widgets... I'm currently having good luck with RN-41XV stuff which is at UART level (0 to 3.3 volts). It's default baud rate is 115200 so that remove the headache of screwing with the inners of the BT module in command mode. The RN-41 is a class 1(good to 300ft), the RN-42 is the same hardware but is a class 2 power output. Class 2 is good for 75ish feet. Most phones/tablets are class 2 BT so even with a class 1 in your ECU the phone can only transmit data up to 75ish feet.

Depending on your skills you can build a small proto board that will hold you BT module and a 3.3v regulator. Connect the rx line to the tx line from the MS2 processor side of the RS232 chip. Then the tx to the rx line from the MS2 processor side of the RS232 chip. I did notice after doing this I could no longer get good data transfer over serial cable as the processor side of the RS232 chip could not drive the UART lines low enough to get a logic 1. One option is to wire up a switch or series of dip switches to disconnect the BT UART line from the RS232 UART lines for when you need to hook a hard line from the laptop to the MS box.

The easy option is to just buy that BT to serial widget from Phil.

From a quick search, it seems that the RN-41XV is not 5V tolerant. So connecting RX/TX directly to the MS CPU is not a good idea and you may well damage the BT module doing this. Using a voltage translator would be the recommended way to go. That should be done when using any 3.3V device that is not explicitly said to be 5V tolerant.

Jean

[ol boy]

Thanks for the heads up. I've had this RN-41 setup working on the wagon for over a year now with the tx-rx/rx-tx tied together.

Is the TX from the S12 chip an open collector then requires the RS232 to idle that line high? If so then the 3.3 volt becomes a non-issue for the TX line.