Reviving An Electron Microscope With Arduino

April 7, 2018 by Tom Nardi 20 Comments

We don’t know about you, but when our friends ask us if we want to help them fix something, they’re usually talking about their computer, phone, or car. So far it’s never been about helping them rebuild an old electron microscope. But that’s exactly the request [Benjamin Blundell] got when a friend from a local hackerspace asked if he could take a look at a vintage Cambridge Stereoscan 200 they had found abandoned in a shed. Clearly we’re hanging out with the wrong group of people.

As you might imagine, the microscope was in desperate need of some love after spending time in considerably less than ideal conditions. While some of the hackerspace members started tackling the hardware side of the machine, [Benjamin] was tasked with finding a way to recover the contents of the scope’s ROM. While he’s still working on verification, the dumps he’s made so far of the various ROMs living inside the Stereoscan 200 have been promising and he believes he’s on the right track.

The microscope uses a mix of Texas Instruments 25L32 and 2516 chips, which [Benjamin] had to carefully pry out after making sure to document everything so he knew what went where. A few of the chips weren’t keen on being pulled from their home of 30-odd years, so there were a few broken pins, but on the whole the operation was a success.

Each chip was placed in a breadboard and wired up to an Arduino Mega, as it has enough digital pins to connect without needing a shift register. With the wiring fairly straightforward, [Benjamin] just needed to write up some code to read the contents of the chip, which he has graciously provided anyone else who might be working on a similar project. At this point he hasn’t found anything identifiable in his ROM dumps to prove that they’ve been made successfully, all he really knows right now is that he has something. At least it’s a start.

More and more of these older electron microscopes are getting a second lease on life thanks to dedicated hackers in their home labs. Makes you wonder if there’s ever going to be a piece of hardware the hacker community won’t bend to their will.

Kniwwelino Is An ESP8266 Micro:Bit

April 5, 2018 by Elliot Williams 12 Comments

Kniwwelino is the latest in a line of micro:bit-inspired projects that we’ve seen, but this one comes with a twist: it uses an ESP8266 and WiFi at the core instead of the nR51 ARM/BTLE chip. That means that students can connect via laptop, cellphone, or anything else that can get onto a network.

That’s not the only tradeoff, though. In order to get the price down, the Kniwwelino drops the accelerometer/magnetometer of the micro:bit for a programmable RGB LED. With fewer pins to break out, the Kniwwelino is able to ditch the love-it-or-hate-it card-edge connector of the micro:bit as well. In fact, with all these changes, it’s hard to call this a micro:bit clone at all — it’s more like a super-blinky ESP8266 development kit.

So what have they got left in common? The iconic 5×5 LED matrix in the center, and a Blockly visual programming dialect dedicated to the device. Based on the ESP8266, the Kniwwelino naturally also has an Arduino dialect that students can “graduate” to when they’re tired of moving around colored blobs, and of course you could flash the chip with anything else that runs on an ESP8266.

We don’t have one in our hands, but we like the idea. An RGB LED is a lot of fun on Day One, and the fact that the Kniwwelino fits so neatly into existing bodies of code makes the transition from novice to intermediate programmer a lot easier. These things are personal preference, but WiFi beats Bluetooth LE in our book, for sheer ubiquity and interoperability. Finally, the Kniwwelino comes in at about half the manufacturing cost of a micro:bit, which makes it viable in schools without large manufacturer subsidies. They’re estimating $5 per unit. (Retail is higher.) On the other hand, the Kniwwelino is going to use more juice than its ARM-based competitor, and doesn’t have an accelerometer.

Kniwwelino is apparently derived from a luxembourgish word “kniwweln” that apparently means to craft something. The German Calliope Mini is named after Zeus’ daughter, the programmer’s muse. We’re stoked to see so many cute dev boards getting into the hands of students, no matter what you call them.

Emulating A Complete Commodore 64

March 28, 2018 by Brian Benchoff 40 Comments

When the Commodore 64 was released in 1982, it was a masterpiece of engineering. It had capabilities far outstripping other home computers, and that was all due to two fancy chips inside the C64. The VIC-II, the video chip for the C64, had sprites and scrolling, all stuffed into a single bit of silicon. The SID chip was a complete synthesizer on a chip. These bits of silicon made the C64 the best selling computer of all time, but have also stymied efforts to emulate a complete C64 system on a microcontroller.

[Frank Bösing] has just managed to emulate an entire C64 on a Teensy 3.6. The Teensy uses an exceptionally powerful microcontroller, but this is a labor of love and code.

The inspiration for this project comes from a reverse-engineered SID chip that was ported to the Teensy 3.2. The SID chip is the make it or break it feature of any C64 emulation, but the Teensy 3.2 didn’t have enough RAM for the most recent versions of reSID. With the release of the Teensy 3.6, [Frank] figured the increased amount of RAM would allow a complete C64 system, so he built it.

The new C64 emulator uses a Teensy 3.6, with a small add-on ‘shield’ (or whetever we’re calling them) to provide connectors for joysticks and the Commodore IEC bus. There’s audio out, support for USB keyboards, and support for an IL9341 SPI display or a regular ‘ol VGA display.

The entire development of this Commodore emulator has been documented over on the PJRC forums, and all the code is over on GitHub. It’s a fantastic piece of work, and as the video (below) shows, this is a real Commodore 64 that fits in your pocket.

Continue reading “Emulating A Complete Commodore 64” →

Evolution Of The ESP8266 Party Button

March 28, 2018 by Tom Nardi 13 Comments

Sometimes the best part of building something is getting to rebuild it again a little farther down the line. Don’t tell anyone, but sometimes when we start a project we don’t even know where the end is going to be. It’s a starting point, not an end destination. Who wants to do something once when you could do it twice? Maybe even three times for good measure?

That’s what happened when [Ryan] decided to build a wireless “party button” for his kids. Tied into his Home Assistant automation system, a smack of the button plays music throughout the house and starts changing the colors on his Philips Hue lights. His initial version worked well enough, but in the video after the break, he walks through the evolution of this one-off gadget into a general purpose IoT interface he can use for other projects.

The general idea is pretty simple, the big physical button on the top of the device resets the internal ESP8266, which is programmed to connect to his home WiFi and send a signal to his MQTT server. In the earlier versions of the button there was quite a bit of support electronics to handle converting the momentary action of the button to a “hard” power control for the ESP8266. But as the design progressed, [Ryan] realized he could put the ESP8266 to deep sleep after it sends the signal, and just use the switch to trigger a reset on the chip.

Additional improvements in the newer version of the button include switching from alkaline AA batteries to a rechargeable lithium-ion pack, and even switching over to a bare ESP8266 rather than the NodeMCU development board he was using for the first iteration.

For another take on MQTT home automation with the ESP8266, check out this automatic garage door control system. If the idea of triggering a party at the push of a button has your imagination going, we’ve seen some elaborate versions of that idea as well.

Continue reading “Evolution Of The ESP8266 Party Button” →

3D Printed ESP8266 Programming Jig

March 27, 2018 by Tom Nardi 20 Comments

The various development boards such as the NodeMCU or Wemos D1 make working with the ESP8266 an absolute breeze. If they have a downside, it is that they are larger than the bare ESP2866, and of course cost a bit more. Just as with the Arduino, once you have the wiring sorted out and the code more or less finalized, your best bet is to ditch the unnecessary support hardware and use the bare module to save space and money in your final design.

The design took a few revisions to get right

Unfortunately, the ESP8266 form factor isn’t terribly forgiving when it comes time for hooking up a programmer. Rather than having to solder a serial adapter to the chip to flash it, [Ryan] came up with a slick 3D printed programming jig that uses pogo pins. If you have to program these boards in bulk, a jig like this can save a massive amount of time and aggravation.

Beyond the 3D printed holder for the pogo pins, this programmer uses a FTDI USB-to-serial adapter, a couple passive components to smooth out the power going into the chip, and a couple buttons.

In the video after the break, [Ryan] walks through the many iterations it took to get the 3D printed aspect of the jig worked out. The design went through a few rather large revisions, including one that fundamentally changed the whole form factor. Even with the jig now working, he mentions that he might circle back around and try it from a different angle.

Programming jigs are a staple of electronics manufacturing, and we’ve covered quite a few that have helped transformed a proof of concept into a small scale production runs.

Continue reading “3D Printed ESP8266 Programming Jig” →

An Introduction To Storm Detector Modules

March 22, 2018 by Sean Boyce 41 Comments

Lightning storm detectors have been around for a surprisingly long time. The early designs consisted of a pair of metal bells and a pendulum. When there was a charge applied, for example by connecting one bell to the ground and the other to a lightning rod, the bells would ring when a lightning storm was close by. In the mid 18^th century, these devices were only practical for demonstration and research purposes, but very likely represent the earliest devices that convert electrostatic charge to mechanical force. A bit over a hundred years later, the first lightning detector was considered by some as the first radio receiver as well.

As soon as I found out about storm detector chips, I knew I would have to get one working. For about $25, I ordered an AMS AS3935 module from China. This chip has been featured before in a number of excellent projects such as Twittering lightning detectors, and networks of Sub-Saharan weather stations. While there’s an Arduino library for interfacing with this IC, I’m going to be connecting it up to an ESP8266 running the NodeMCU firware, which means digging into the datasheet and writing some SPI code. If any of the above tickles your fancy, read on! Continue reading “An Introduction To Storm Detector Modules” →

Control A Swarm Of RC Vehicles With ESP8266

March 17, 2018 by Tom Nardi 9 Comments

Over at RCgroups, user [Cesco] has shared a very interesting project which uses the ever-popular ESP8266 as both a transmitter and receiver for RC vehicles. Interestingly, this code makes use of the ESP-Now protocol, which allows devices to create a mesh network without the overhead of full-blown WiFi. According to the Espressif documentation, this mode is akin to the low-power 2.4GHz communication used in wireless mice and keyboards, and is designed specifically for persistent, peer-to-peer connectivity.

Switching an ESP8266 between being a transmitter or receiver is as easy as commenting out a line in the source code and reflashing the firmware. One transmitter (referred to as the server in the source code) can command eight receiving ESP8266s simultaneously. [Cesco] specifically uses the example of long-range aircraft flying in formation; only coming out of the mesh network when it’s time to manually land each one.

[Cesco] has done experiments using both land and air vehicles. He shows off a very hefty looking tracked rover, as well as a quickly knocked together quadcopter. He warns the quadcopter flies like “a wet sponge”, but it does indeed fly with the ESP’s handling all the over the air communication.

To be clear, you still need a traditional PPM-compatible RC receiver and transmitter pair to use his code. The ESPs are simply handling the over-the-air communication. They aren’t directly responsible for taking user input or running the speed controls, for example.

This isn’t the first time we’ve seen an ESP8266 take the co-pilot’s seat in a quadcopter, but the maniacal excitement we feel when considering the possibility of having our very own swarm of flying robots gives this particular project an interesting twist.