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I searched the forums to see if anyone else had this problem, and I could only find this thread (which was never answered), and this thread, which is indirectly related and will be more useful once I get over this hurdle. If I missed a link that you think will help me, please let me know. I don't have a strong electronics background, but I have been getting guidance from someone who has, so bear with me if I did something stupid.
Here's my situation: I have a Netduino Mini, a basic solderless breadboard, and an FTDI Basic Breakout 5V. I have a separate 5V 2A adapter to provide power to the Netduino. Here is how I have things wired:
From FTDI USB to Netduino:
FTDI GND->Pin 4 GND on Netduino
FTDI DTR->Netduino DTR
FTDI TX->Netduino RX
FTDI RX->Netduino TX
From power source, to breadboard, I have the leads connected (+ on power to Va on board, - to Vb on board). From Va, I have another wire going to the positive voltage column to ensure that any wire in it will get 5.0V.
From Netduino to power, I have the +5.0V pin (pin 21) connected to a pin in the positive voltage column. Since I am not using pin 24, pin 21 should be for +5.0V input.
While my PC has no problem connecting to the FTDI and recognizing it, when I connect to the COM port associated with that USB port, I see no communications from the chip: it's just a black screen.
In connecting my Netduino to the power, did I brick it? Did I make a connection from the FTDI to the Netduino that is affecting communication?
I have attached pictures so you can see exactly what I did.
Is the power supply you are using a regulated power supply? Did you try powering the Netduino by the 5V pin of the breakout board?
I believe that no discovery of fact, however trivial, can be wholly useless to the race, and that no trumpeting of falsehood, however virtuous in intent, can be anything but vicious.
-- H.L. Mencken, "What I Believe"
Here's my situation: I have a Netduino Mini, a basic solderless breadboard, and an FTDI Basic Breakout 5V. I have a separate 5V 2A adapter to provide power to the Netduino. Here is how I have things wired:
From FTDI USB to Netduino:
FTDI GND->Pin 4 GND on Netduino
FTDI DTR->Netduino DTR
FTDI TX->Netduino RX
FTDI RX->Netduino TX
I don't have this part but I do have an FTDI cable and this is the wiring I use:
Power supply +5V to pin 21
Power supply GND to pin 23
FTDI GND to pin 23
FTDI Tx to pin 12
FTDI Rx to pin 11
From you wiring it looks like you have wired the DTR on the FTDI cable to the DTR on COM2 (which by the way uses RS232 voltages +/- 12V). I don't use this to talk to the Mini, just Tx and Rx.
Have you deployed an application to the Mini yet? Just wondering because if memory serves, they ship with a transport selection app on them. The getting started guide is in the forums here.
Is the power supply you are using a regulated power supply? Did you try powering the Netduino by the 5V pin of the breakout board?
The power supply I have is this 5V 2A AC Adapter; Since it is outputting as DC, I presume it is regulated, but maybe the problem is that rated output is no matching what is written on the adapter? And yes, I did try powering the Netduino on the 5V pin...nothing seemed to happen.
From you wiring it looks like you have wired the DTR on the FTDI cable to the DTR on COM2 (which by the way uses RS232 voltages +/- 12V). I don't use this to talk to the Mini, just Tx and Rx. Have you deployed an application to the Mini yet?
I wasn't sure that DTR was needed, but if that is the case, should I remove it or leave it where it is? Thank you for the link: I have seen this, but the power area is where I think I am hung up. I prefer to use my 5V adapter as regulated input, but, come to think of it, if I wrap two wires around a 9V battery, I could get just what I need from that instead...
Update:
After changing power sources and configurations (I decided to use a simple 9V battery to power the Netduino, used pin24 to receive power, then attached TX and RX to pins 1 and 2 instead of 11 and 12), then straightening the FTDI connections to the board (apparently, they are not stable...still working on it), I saw some gibberish being written to the screen and the RX and TX LEDs on the breakout board light up.
It looks good so far, but is the garbage expected? I set my communication settings to 115200 baud, 8 data bits, 1 stop bit, no parity, no flow control.
I think I can follow the basics from now and join the rest of the crowd. Thank you both for your help once more!
After changing power sources and configurations (I decided to use a simple 9V battery to power the Netduino, used pin24 to receive power, then attached TX and RX to pins 1 and 2 instead of 11 and 12), then straightening the FTDI connections to the board (apparently, they are not stable...still working on it), I saw some gibberish being written to the screen and the RX and TX LEDs on the breakout board light up.
Pins 1 and 2 use RS232 logic levels (+/-12V) but the FTDI cable you provided the link for suggests it is TTL. The final paragraph reads:
One of the nice features of this board is a jumper on the back of the board that allows the board to be configured to either 3.3V or 5V (both power output and IO level). This board ship default to 5V, but you can cut the default trace and add a solder jumper if you need to switch to 3.3V.
To me, this suggests that the board is using 0V and 5V for the logic levels (i.e. TTL) and not +/-12V (i.e. RS232).
To me, this suggests that the board is using 0V and 5V for the logic levels (i.e. TTL) and not +/-12V (i.e. RS232).
Ok, I see. By that logic then, pins 1 and 2 should not yield anything. I looked at the schematics on the FTDI, and I cannot seem to determine anything on this. What I will try to do tomorrow is switch back to 11 and 12 and see what happens: several changes were made, and likely, the TX RX pin change may not make a difference.
Ok, I see. By that logic then, pins 1 and 2 should not yield anything. I looked at the schematics on the FTDI, and I cannot seem to determine anything on this. What I will try to do tomorrow is switch back to 11 and 12 and see what happens: several changes were made, and likely, the TX RX pin change may not make a difference.
Trial and error is often not a good way to approach electronics - you might damage your components
Programming
To deploy a Netduino Mini app (and debug), you'll use serial communication. Here are a few options.
* BASIC Stamp board: just plug the Netduino Mini into the BASIC Stamp 2-compatible board and use the existing serial cable/virtual serial port (USB) connectivity.
* RS232: cut the end off of an RS232 cable and wire the RX, TX, DTR, and GND wires to pins 1, 2, 3, and 4. Or use an RS232 breakout adapter (with the same wiring--but no cable cutting).
* 3.3V TTL: attach a 3.3V TTL cable to pins 11 (cable's RX) and 12 (cable's TX). Attach the cable's GND connector to pin 4. If the cable has a DTR wire, connect that to pin 3.
In Visual Studio, set the deployment to Serial instead of USB and select your COM port. That's it. [If you're using TTL via pins 11 and 12, read the following section.]
Switching serial deployment port
The Netduino Mini may be programmed over its RS232 UART (pins 1, 2) or its 3.3V TTL UART (pins 11, 12). By default it uses the RS232 UART.
If you want to use the 3.3V TTL UART (pins 11, 12) instead:
* Connect your computer to the 3.3V TTL UART (pins 11, 12).
* Open a serial connection to your board (115200 bps, No parity, 8 data bits, 1 stop bit, no flow control) using Putty, HyperTerminal, Tera Term or other terminal software.
* Press ESC. You will see a prompt offering to let you select the deployment/debug port.
* Select the TTL UART (COM1).
* You will see the Netduino Mini reboot and start sending debug data over the port.
Note that you need 3.3V logic levels, you can utilize that with your ftdi board with a solder jumper.
I believe that no discovery of fact, however trivial, can be wholly useless to the race, and that no trumpeting of falsehood, however virtuous in intent, can be anything but vicious.
-- H.L. Mencken, "What I Believe"
Heh, you are correct Stefan about experimentation...no doubt.
I have read these instructions before, but I never drew a connection between the FTDI and the part about setting it to TTL UART (pins 11 and 12) until now. I think I am going to set the jumper board to 3.3V. You say that this can be done by adding a solder jumper, and according to the product's page:
This board ship default to 5V, but you can cut the default trace and add a solder jumper if you need to switch to 3.3V.
How do I go about doing this? I also picked up a logic level converter that can go from 5->3.3->5V. This looks like just the place for it...maybe I will use that instead.
I have read these instructions before, but I never drew a connection between the FTDI and the part about setting it to TTL UART (pins 11 and 12) until now. I think I am going to set the jumper board to 3.3V. You say that this can be done by adding a solder jumper, and according to the product's page:
If you are doing this to connect to the TTL UART then you do not need to - the pins will take 5V.
Just thought - will the Rx on the FTDI pick up the 3.3V logic level - Hmmmmmm.
That might just be it...we can't get a complete flow. As I had mentioned earlier, I have a logic level converter that can do 3.3 to 5V and back (see here). If this is the route I'd take, I presume I'd just route the Tx on the Netduino to the HV Tx on the converter, then run another from the breakout to the HV Rx on the same channel?
That might just be it...we can't get a complete flow. As I had mentioned earlier, I have a logic level converter that can do 3.3 to 5V and back (see here). If this is the route I'd take, I presume I'd just route the Tx on the Netduino to the HV Tx on the converter, then run another from the breakout to the HV Rx on the same channel?
I think you need all of the Mini connections on the LV side. So put 3.3V and GND to the LV connector in the middle then connect the Mini Tx to RxLV and the Mini Rx to TxLV. This does the cross over of Tx and Rx for you.
On the other side, put 5V and GND to the HV connector in the middle. Then connect the FTDI 5V Tx to TxHV and FTDI Rx to RxHV. No need to cross over Rx and Tx as we have done this on the LV side.
That sounds like it will work. However, I took a look at the FTDI just now, and I have a 3V3 pin on it: I presume this means 3.3V output. I currently have this wire connected. Might this be causing a problem? Because it's outputting something, the input voltage drops below what is expected for registration of signal coming back from the Netduino? None of the Netduino pins were in the same row or column as this 3v3, so there should be no damage to the pins.
I think you need all of the Mini connections on the LV side. So put 3.3V and GND to the LV connector in the middle then connect the Mini Tx to RxLV and the Mini Rx to TxLV. This does the cross over of Tx and Rx for you.
On the other side, put 5V and GND to the HV connector in the middle. Then connect the FTDI 5V Tx to TxHV and FTDI Rx to RxHV. No need to cross over Rx and Tx as we have done this on the LV side.
I tried this just now...still nothing. The LEDs don't even light up anymore. I think I am just going to order a proper FTDI cable and see if I can return this breakout...it doesn't seem to be performing right. Thanks for your help.
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