Search found 101 matches

by languer
Sat Sep 22, 2018 10:09 am
Forum: SparkFun Product Questions
Topic: Sparkfun Openscale - uploading my own code/firmware
Replies: 14
Views: 381

Re: Sparkfun Openscale - uploading my own code/firmware

I think you are asking if you can write to the Arduino EEP (i.e. the ATMEGA 328P EEP) externally. The short answer is that there is no connection between the external world and the internal EEP of the ATMEGA IC. Having said that, it seems you could "build" your interface within the Arduino code and ...
by languer
Fri Aug 24, 2018 11:27 pm
Forum: Projects
Topic: AM/FM tuner (SI4731)
Replies: 5
Views: 149

Re: AM/FM tuner (SI4731)

That is a very cool hot plate setup. If you already have another QFN, and are doing smt stencils, then I think QFN is the way to go.
by languer
Fri Aug 24, 2018 12:17 am
Forum: SparkFun Product Questions
Topic: Openscale returning negative values?
Replies: 2
Views: 119

Re: Openscale returning negative values?

Did you reverse the + and - sense wires?
by languer
Fri Aug 24, 2018 12:16 am
Forum: Projects
Topic: AM/FM tuner (SI4731)
Replies: 5
Views: 149

Re: AM/FM tuner (SI4731)

I don't think the QFN package will provide much better results just because. Getting that damn pad at the bottom of the package properly mounted is not trivial. The main thing is that you have a good ground plane, that the copper underneath the IC (i.e. the next layer down) is ground and you don't h...
by languer
Tue Aug 21, 2018 10:36 pm
Forum: Projects
Topic: AM/FM tuner (SI4731)
Replies: 5
Views: 149

Re: AM/FM tuner (SI4731)

Have you compared your layout to Sparkfun's Si4703 board? I would look very closely at you power supply decoupling around the Si4731, and even more closely at the grounding for the Si4731 (e.g. are you using the part with the exposed pad and is it grounded?, are you using a good ground plane underne...
by languer
Sun Aug 12, 2018 8:01 pm
Forum: SparkFun Product Questions
Topic: Sparkfun Openscale - uploading my own code/firmware
Replies: 14
Views: 381

Re: Sparkfun Openscale - uploading my own code/firmware

Created a brief article on a prototype weight scale using SFE's OpenScale platform. You can read it here: https://www.electro-tech-online.com/art ... scale.859/
by languer
Sat Aug 04, 2018 9:37 am
Forum: SparkFun Product Questions
Topic: Sparkfun Openscale - uploading my own code/firmware
Replies: 14
Views: 381

Re: Sparkfun Openscale - uploading my own code/firmware

Another option (not sure how likely it is) would be to try to split the ATMEGA oscillator to also feed the HX711 clock input. Turns out the ATMEGA328 has the capability to output the system clock into pin PB0. To do this you have to burn a new bootloader with the CLKOUT fuse set. Then you need to c...
by languer
Wed Aug 01, 2018 11:59 pm
Forum: SparkFun Product Questions
Topic: Sparkfun Openscale - uploading my own code/firmware
Replies: 14
Views: 381

Re: Sparkfun Openscale - uploading my own code/firmware

If you look at the datasheet of the HX711 (sh 4, under Clock Source Options) you see you can drive this externally. from HX711 datasheet: By connecting pin XI to Ground, the on-chip oscillator is activated. The nominal output data rate when using the internal oscillator is 10 (RATE=0) or 80SPS (RATE...
by languer
Wed Aug 01, 2018 1:31 am
Forum: SparkFun Product Questions
Topic: Sparkfun Openscale - uploading my own code/firmware
Replies: 14
Views: 381

Re: Sparkfun Openscale - uploading my own code/firmware

Final example code (stores the calibration in EEPROM). /* Example HX711 code using OpenScale @languer 2018 This example demonstrates basic scale output. See the calibration sketch to get the calibration_factor for your specific load cell setup. Arduino pin 3 -> HX711 CLK (modified to work with open ...
by languer
Mon Jul 30, 2018 7:48 am
Forum: SparkFun Product Questions
Topic: Sparkfun Openscale - uploading my own code/firmware
Replies: 14
Views: 381

Re: Sparkfun Openscale - uploading my own code/firmware

Glad you have it working. Below is the code I played with over the weekend. /* Example HX711 code using OpenScale @languer 2018 This example demonstrates basic scale output. See the calibration sketch to get the calibration_factor for your specific load cell setup. Arduino pin 3 -> HX711 CLK (modifi...
by languer
Sat Jul 28, 2018 3:03 pm
Forum: SparkFun Product Questions
Topic: Sparkfun Openscale - uploading my own code/firmware
Replies: 14
Views: 381

Re: Sparkfun Openscale - uploading my own code/firmware

The simple program I provided works. I had a mistake on the #define (which I corrected on the comment section, but missed on the actual #define). Now that I got an OpenScale I was able to try it.
you can see it working by changing

Code: Select all

#define DOUT  3
#define CLK  2
to

Code: Select all

#define DOUT  2
#define CLK  3
by languer
Wed Jul 25, 2018 12:05 am
Forum: SparkFun Product Questions
Topic: Sparkfun Openscale - uploading my own code/firmware
Replies: 14
Views: 381

Re: Sparkfun Openscale - uploading my own code/firmware

I think the code below should get you going (from a simplicity point of view). It is taken almost verbatim from SFE's HX711 examples. The Openscale system is more elaborate and has eeprom to store things, user interface, temp sensor, etc. The code below is just an attempt to simplify things. I don't...
by languer
Mon Jul 23, 2018 11:17 pm
Forum: SparkFun Product Questions
Topic: Sparkfun Openscale - uploading my own code/firmware
Replies: 14
Views: 381

Re: Sparkfun Openscale - uploading my own code/firmware

I don't have the OpenScale system but after reading the info from SFE it seems the system is based on the Load Cell Amplifier HX711 . The HX711 SFE library seems pretty straight forward to use. Look at the SFE examples from it and I would start by using them. Also, if you look at the original HX711 ...
by languer
Mon May 14, 2018 11:16 pm
Forum: SparkFun Site Questions/Comments
Topic: Low Cost GPIB to USB Controller
Replies: 3
Views: 325

Re: Low Cost GPIB to USB Controller

@darrellg ; You are probably right. Keep in mind though that SFE already carries a GPIB to USB controller. And also that most HAM and used equipment comes with GPIB interface. Two others facts. My main thing was to bring awareness; it took me a few days of searching to stumble into that controller.
by languer
Sat May 12, 2018 11:32 am
Forum: SparkFun Site Questions/Comments
Topic: Low Cost GPIB to USB Controller
Replies: 3
Views: 325

Re: Low Cost GPIB to USB Controller

I am updating the link to my experience with the device to this one as I learned that the previous link requires a login.