openrcforums

No, the capacitor on pin 3 can't block only the PWM frequency, it just doesn't work that way. The "roll off" is not fast enough. To block the PWM we have to partially block some of the higher audio frequencies. That's why I'm looking into multiple RC filters. A single RC filter rolls off a...

The TelemetrEZ board has nothing to do with the backlight. If you look at my code in er9x, you will see all I do is detect the 'PRIVATE' data arriving on the serial port, and change the two pins used for the switches to outputs, then copy the values from the TelemetrEZ board data into them. That way...

Perhaps a TWIN-T filter would work (3 resistors and 3 capacitors). I will need to calculate the effect on lower frequencies though to see if it is good enough. I'll get to it, trying to progress ersky9x at the moment. Really could do with someone else doing a few things, but everyone else seems to b...

Quickly moved on to r126! Just a few tweaks to do with the GVARS. A GVAR may be used for the offset and/or the weight of a mix. Should work correctly now. Trying to get GVARs working for expo and dual rate, but there are some funny editing problems, values change just when you press left or right to...

One problem you might have is the PWM noise at 46.875 kHz cannot be heard itself, but if the LM386 is driving it out you will get extra current consumption.
Might be worth measuring how much current is being taken by the voice module when idle.

Mike.

On the main screen, press UP or DOWN until you get to the screen with 8 horizontal bars at the bottom. When you move the throttle stick, does one of the bars move from the end of one side to the end of the other? If so, then the Tx is setup correctly. As Rob says, the next test is a servo on the thr...

Why do not you use a 328 with 20MHz? As indicated later, we would need to run it from a 5 volt supply, then we would need to translate to logic levels to 3.3 volts for the SD card. We have chosen to use 3.3 volts, and use an already proven method of translating to the 5 volt logic of the main M64 p...

Both er9x and open9x have many features. open9x was 'branched' from er9x, and both have developed since that time. Because they were at one time the same, many of the basic features are the same in both. Open9x has more features, mainly because there are more people working on it. However, on the st...

Your stick calibration seems to be OK then, it is something in your mixes or dual rate causing the problem.

Mike.

How low does the earphone output need to be? When we know that, we can decide the best implementation.

Mike.

r123 now available. Rotary encoder now steps through all items on a menu, going across each row, then down to the next row. Current calibration moved to ANA menu. This is the Tx current measurement. Co-processor version now on Firmware version menu, at the bottom. Various other cosmetic changes. Lim...

If you can, try changing the 47nF to 22nF, and adding a 2.2nF at pin 3. This should be no worse on the PWM frequency, but give better output at 8kHz.

Mike.

What we really need is either a much higher PWM frequency, not really possible, a DAC, again not really possible without making the board bigger and more expensive, or a low pass filter with a VERY sharp cutoff. You are looking to pass frequencies up to 11 kHz, while supressing 46.875 kHz. Now, on t...

To check the interface to the M64 I'm going to need to write some code for er9x, and probably put something into the application in the voice module as well. I wasn't about to do that. Using the serial to the M64 is a little way down the line.

Mike.

Lets just check a few things. You have er9x. On the main screen you have two squares, with little circles in them. These circles move with the sticks, so when you move the throttle stick, does the little circle that moves go from one side of the square to the other?

Mike.

OK, here's a cardboard replica of a voice module: NO surface mount components.
It's 30.5 mm by 79 mm, and mounts on the 'spare' holes on the gimbals, I was checking it fitted OK.
This is a fully tracked, 2-sided PCB layout.

Mike.

I can't detect any buzzing at lower volume settings on mine. I think I'm using 16kHz, 8-bit files, maybe 16kHz 16-bit files, but not 22kHz files.
If you are using 22kHz files, could you try with some 16kHz files?

Mike.

When calibrating, did you put the throttle stick to the mid position at the start? Having it at the bottom at the start of calibration causes the symptom you describe.

Mike.

I just double checked and loaded the bootloader and application from the zip file, all works fine. I have, however, now done some small changes to the application. I had a 0.2 secs delay at startup, that will not be needed if the bootloader runs first as it has a 0.5 sec delay. I've also turned busy...

I thought all the circuits on here had a pull up resistor on pin 1 anyway.

Mike.

There is a version of er9x, called ersky9x, that is installed on the sky9x board when you receive it. Both ersky9x and open9x were created/adapted for this board.

Mike.

Not a 'real' STK500 then!
Yes to the download and flash with the serial programmer.
Yes, to the reset, just ground pin 1. If you load the original application, and want to get the bootloader running again just power on, then ground pin 1 and the bootloader should be running.

Mike.

Yes, using the STK500 will erase the chip, bootloader and appliocation. My suggestion is to use the bootloader to flash the original application, so you still have the bootloader present. This will help test to see if the bootloader is causing the welcome message to be missing. To get the bootloader...

Joao: My volume and welcome message are OK. No you don't need to remove the SD card if flashing using the serial interface. You could flash the original application and see if the welcome message comes back. This will help find whether the problem is due to the bootloader, or the new application. Th...

Sounds possible, I don't know it specifically. Is it USB to serial?
FrSky also do that module to convert logic to RS232 levels that many use in the telemetry mod.

Need to pack up now.

Mike.

Yes, it's logic level, so the signals are the wrong way up. Three solutions: 1. Try connecting the FTDI to the two signals that would go to the M64, these are for 5 volt logic signals. 2. Change the EEPROM in the FTDI chip to invert tha TXD and RXD signals, change the EEPROM ack afterwards! Quote fr...

Now, FTDI disconnected from the board and connected to USB, both TX and RX are at 5V WRONG! It looks like this FTDI board is running at logic levels, not serial RS232 levels the board is looking for. I've been using 'proper' USB to serial devices that give RS232 voltages (+/- 6 volts). You could tr...

This viewtopic.php?f=5&t=948&start=1950#p28528 schematic?
The signal labelled PCTXD is the TXD from the PC and is the one to connect to +5/6 volts. It should be safe with +/- 12v connected as that is what is allowed for the serial signals.

Mike.

That's good for the fuses. Because you are using the SPI for programming, the SPIEN fuse is locked as active, hence the odd checkbox. With the FTDI disconnected, check pins 2 and 3 of the processor are at 3.3 volts. Then connect the external RXD signal (not the one going to the M64) to 5 volts (mayb...

It's using the STK500 protocol. Usual first check, have you got Tx and Rx the right way round? The TXD signal from the voice module goes to the RXD of the FTDI.
Oh, and please confirm your fuse settings.

Mike.