I fixed the battery icon bug now. I had forgot to test it with less than full battery
I guess I could get rid of the second keypress. It’s there because e.g. hello world and other simple applications exit immediately, and I want to see the screen after they exit.
The programs are on the 2MB flash memory. There can be as many as can fit, probably about 20-40 because each app is about 50-100kB.
The programs are in the pawn bytecode. Pawn has a p-code interpreter for ARM that is written in assembler (written by someone else, not me). It is quite fast, only about 5-10 instructions per one emulated instruction.
The programs are loaded to RAM at runtime. However, Pawn has an ‘overlay’ mechanism that is kind of swap. It allows to load programs larger than 32kB. The interpreter will then reload functions from flash as needed, always keeping the most recent functions in RAM.
The program size is kind-of limited by the data size - because data memory is never swapped, you can only have about 20kB of data in order to leave enough space for functions. Of the programs I have done so far, only frequency response app requires the overlays. So I guess programs larger than frequency response have to be a bit careful about memory use.
Only list of functions so far is the .inc files here:
Indeed, that is a possibility worth considering. It may be too tight on the RAM memory, though. Both the main app and pawn require quite much all the available RAM on the device, so it is difficult to make them run at the same time. One could make a key that easily switches between them, though.
Processing data from main app is already possible by reading the files it creates. I have been thinking that a BMP viewer application would be useful if one wants to use the Quad completely stand-alone
I just finished a simple Spectrum Analyzer using Petteri’s implementation of PAWN and all I can say is that Petteri has provided a great tool. I have started from scratch on many small platforms over the years and this has been the quickest and easiest experience I have ever had in doing this. My little app is called spec_an and can be found with Petteri’s examples at <LINK_TEXT text=“https://github.com/PetteriAimonen/QuadP … r/Programs”>https://github.com/PetteriAimonen/QuadPawn/tree/master/Programs</LINK_TEXT>. Based on what I did I think the very best way to get on top of this is to study a few of the posted programs and then browse through the include files.
Is there possibility to turn off the screen? I haven’t found anything in includes.
I would like to analyse battery discharging process. It takes a lot of time. I suppose backlight use a lot of energy, so if I could turn off the screen I could longer measure.
Not right now. Should be easy enough to add support in runtime once I get around to it (also missing beeper support currently). You can keep the DSO connected through USB if you worry about battery running empty.
I’d add controlling RTC to wishlist - of course if there is RTC on board. Setting time only (without date) would be useful for me, even if I have to set after every power on (or even after application start). I’m working on project (for now “secret” where I’d like to synchronize asynchronous (user triggered) data dumps with position (from GPS).
Yes, I know. I’m going to check “2xAA USB charger” so for now it’s no problem
This is what I’m using as workaround. But this gives me timestamp relative to power on - every time is similar. Of course using “select_filename” I have files in chronological order.
btw. I’m impressed how easy you can write an application. You don’t have to learn PAWN - just use it.
Hmm yeah, I wonder if there is any reasonable solution to this. One common way to easily set RTC of USB devices is to monitor timestamp on files written to USB drive. Then just sync the time right after the write.
Also if I added proper power saving support to the Pawn runtime, it could possibly be left on for a long time. Most power-consuming parts of the system (ADC, FPGA, switching regulator) can be switched off and MCU could go into standby. The standby current consumption should be less than 1mA, giving a few weeks of standby time.
Too bad that they didn’t make use of the RTC in the microcontroller. Would have required just two diodes (to drop 4.2V -> less than 3.6V) if one is happy with LSI oscillator accuracy (can calibrate it right before sleep).
Added beeper.amx that simply beeps when it detects a voltage on input. Also gives 1 V voltage on waveout, so with two probes it can be used to check conductivity of e.g. PCB traces. https://github.com/PetteriAimonen/QuadPawn/wiki/Beeper
The calibration app, is this just for pawn apps or is it the same calibration that can be done in the dso firmware and its effect is system wide for the entire device and its apps?
Yeah I have been thinking about it for a while but haven’t had time to implement it.
Should be quite easy atleast to write to serial, because a simple printf() from the code is enough. Reading will require some IRQ routine so that it will store the characters as they arrive.