As you dive deeper into the world of electronics, a good oscilloscope quickly is an indispensable tool. However, for many use cases where you’re debugging low voltage, low speed circuits, that expensive oscilloscope is using only a fraction of its capabilities. As a minimalist alternative for these use cases [fhdm-dev] created Scoppy, a combination of firmware for the Raspberry Pi Pico and an Android app to create a functional oscilloscope.
As you would expect, the specifications are rather limited, capturing a maximum of 100 kpts at a speed of 500 kS/s shared between the two channels. Without some additional front end circuitry to protect the Pico, the input voltage is limited to 0-3.3 V. Neither the app nor the firmware is open source, and getting access to the second channel and removing ads requires a ~$3 in-app purchase. Even so, we can still think of plenty of practical uses for a ~$7 oscilloscope. If you do decide to add some front-end circuitry to change to voltage range, you can set them in the app, and switch between them by pulling certain GPIO pins high or low. The app has most of the basic oscilloscope features covered, continuous and single shot capture, adjustable trigger settings and a scalable waveform display.
Simple, cheap oscilloscopes like these have their place, but you start to understand why the “real” ones are so expensive when you see what goes into developing a high performance oscilloscope.
[Aaron Christophel] writes in with yet another clever hack for his D6 Fitness Tracker. Using OpenOCD and Pygame, he shows how you can pull data right off the tracker’s screen and sent it to the computer.
This one appealed to us for its brevity. First [Aaron] launches the OpenOCD server which connects to the D6. Then, a short Python script connects to the server through telnet, reads the screen data, and uses a look-up table to turn the data into a duplicate display on the PC screen. If you’re more of a visual learner, there’s a demonstration video after the break.
The D6 is a popular fitness tracker that’s often re-branded and sold at a very low cost. [Aaron] is a big fan of these Nordic nRF52 powered devices, and we’ve covered some of his hacks before. If you’d like to learn more about these interesting little devices there’s quite a write-up on their inner-workings here.
Continue reading “Pulling Display Data Off Of A Fitness Tracker”
Over the last several months, [Aaron Christophel] has been working on creating a custom firmware for cheap fitness trackers. His current target is the “D6 Tracker” from a company called MPOW, which can be had for as little as $7 USD. The ultimate goal is to make it so anyone will be able to write their own custom firmware for this gadget using the Arduino IDE, and with the release of his new Android application that allows wirelessly flashing the device’s firmware, it seems like he’s very close to realizing that dream.
Previously, [Aaron] had to crack open the trackers and physically connect a programmer to update the firmware on the NRF52832-based devices. That might not be a big deal for the accomplished hardware hacker, but it’s a bit of a hard sell for somebody who just wants to see their own Arduino code running on it. But with this new tool, he’s made it so you can easily switch back and forth between custom and original firmware on the D6 without even having to take it off your wrist.
After the break, you can see the video that [Aaron] has put together which talks about the process of flashing a new firmware image. It’s all very straightforward: you simply pick the device from the list of detected BLE devices, the application puts the tracker into bootloader mode, and then you select the DFU file you want to flash.
There are a couple of ready-made firmwares you can put on the D6 right now, but where’s the fun in that? [Aaron] has put together a customized version of the Arduino IDE that provides everything you need to start writing and flashing your own firmware. If you’ve ever dreamed about creating a wearable device that works exactly the way you want, it’s hard to imagine a cheaper or easier way to get in on the action.
When we last heard from [Aaron] earlier this year, he was working on the IWOWN I6HRC tracker. But it looks like the availability of those devices has since dried up. So if you’re going to try your hand at hacking the MPOW D6, it might be wise to buy a few now while they’re still cheap and easy to find.
Continue reading “OTA Flash Tool Makes Fitness Tracker Hacking More Accessible”
I’ll admit it. I can be a little cheap. I also find it hard to pass up a bargain. So when I saw a robot kit at the local store that had been originally $125 marked down to $20, I had to bite. There was only one problem. After I got the thing home, I found they expected you to supply your own radio control transmitter and receiver.
Normally, that wouldn’t be a problem but lately… let’s just say a lot of my stuff is in storage and I didn’t have anything handy. I certainly didn’t want to go buy something that would double the cost of this robot that I really didn’t need to begin with.
However, I did have a few ESP8266 modules handy. Good ones, too, from Adafruit with selected 5 V I/O compatibility and an onboard regulator. I started thinking about writing something for the ESP8266 to pick up data from, say, a UDP packet and converting it into RC servo commands.
Seemed like a fair amount of work and then I remembered that I wanted to try Blynk. If you haven’t heard of Blynk, it is a user interface for Android and Apple phones that can send commands to an embedded system over the Internet. You usually think of using Blynk with an Arduino, but you can also program the embedded part directly on an ESP8266. I quickly threw together a little prototype joystick.
Continue reading “The Joy Of The ESP8266 And Blynk”