April 4, 2023 update

uMyo v3 is officially out and in stock! It is now smaller and has separate battery charger. Release notes:

• changed board design for more dense placement and easier connection of multiple units
• added on-board compass in addition to IMU in v2. Orientation tracking now has no drift!
• moved on-board charger to a separate charging board (included in kits), reducing uMyo size and weight
• changed chip to nRF52832 instead of nRF52810 (due to chips availability)
• added CR2032 operation mode with LED turned off to minimize power consumption, single battery can provide ~4 hours of operation for one uMyo

What is it?

It's a first ever open source hardware wireless EMG wearable device with hybrid wet and dry electrodes - as far as we know of. We've been working on uMyo for some time, and we know a lot of people have been waiting for it. Well, the wait is finally over! You can read more about uMyo development on our Hackaday blog. It's also our second device that we will be selling, besides uECG.

What's special about it?

There were open source EMGs before (most prominent example is Sparkfun Myoware), but they weren't wireless, which is absolutely critical for signal quality. And there were wireless EMG devices (like Myo Armband), but they weren't open source. And none of them had possibility to work with dry and wet electrodes on the same device.

One uMyo device is a single-channel EMG. It's lightweight and inexpensive, and it's also modular - you can combine several devices and get multi-channel EMG. It can be used as a development platform for projects using muscle signals, for research, rehabilitation, or to control things on a computer or in the real world. It would be most useful to researchers and students, makers and hardware/software developers, and medical professionals, especially the ones working with physical therapy.

We're opening uMyo v3 sales!

We are launching sales of another 50 devices.

First orders may be shipped with a slight delay, but normally we will try to ship them within 3 days.

Device limit per order and pricing

The pricing can change a bit on further batches. It can go up or down, but we do not expect it to be radically different, as our goal is to make uMyos affordable. Our priority right now is that everyone who has been waiting for a new EMG sensor for their projects could get a device (or two) to test and experiment with. You can actually order up to 3 devices, and we even lowered base shipping rate for that, primarily because of Europe customs limit, but also for the rest of the countries. However, for testing purposes it would be best if more separate people could order and experiment the devices. And also, we don't really have tutorials for multiple devices yet. So it's best to only order 2+ devices if you know what you're doing.

Please don't order more than 3 devices to Europe, as this will go over 150 EUR customs limit! If you do that, we will refund the order, as we can't ship them for now. For UK: additionally, please don't order more than 2 devices to the UK, as only EMS shipping is available to your country and shipping with it will go over the customs limit. Please read general disclaimer about Europe below.

Feedback: We have a Discord server here! https://discord.gg/dEmCPBzv9G We will be very glad if you share your projects and feedback there. Also, you can receive support from the team and community there. If you don't have Discord, you can also contact us here on Tindie, on any of our social networks (links are here), or by email: hi@ultimaterobotics.com.ua

Disclaimer about batteries: uMyos are sold without the lipo or CR2032 batteries! You can use ones you have at hand or buy a new one from somewhere. You'll want the ones with 2 mm JST connectors - we have some product links on this Hackaday post. Because of this decision, we were able to lower the device cost and sell it to you cheaper, and it greatly simplifies the logistics. This is because we have to ship batteries to us by sea and it's very slow, and then there are some issues with shipping them to buyers by air, because postal services don't like to ship batteries inside packages, especially more than one. Besides, a lot of people already have lipo batteries at home from other projects. Also, as of v3, you can power a single uMyo from a CR2032 battery. They're easily available and you can test uMyo with them until you get lipo ones. One CR2032 can last for about 3 hours of testing.

Disclaimer for buyers from Europe: 1) You'll have to pay VAT when receiving the package. Tindie doesn't have IOSS yet (like eBay, Etsy and other major platforms), so we can't collect VAT when you order. Sorry for that! 2) For now, please don't order more than 3 devices to Europe so the total order (including shipping) doesn't go over 150 EUR. We adjusted the prices so 3 devices can still fit, plus shipping. Also, because of that, we currently only offer standard air mail for Europe, as to not go over the limit. It should be still rather fast these days, at least until New Year.

Disclaimer for buyers from the UK: The above rules about Europe apply. Additionally, please don't order more than 2 devices. Because standard air mail does not track reliably for the UK, we can only ship to you with EMS, and this will make the order amount go over 150 EUR limit.

Sorry for all of the limits! Hopefully it will change in the future, but we have to set them for now.

If you're not from Europe, proceed normally.

Now that the introduction is over, here's more details about the device!

Features and how to use:

• It's wireless! No more mess of wires when working with EMG
• Works with any Arduino via nRF24 radio module (we wrote an Arduino library for that)
• Works with ESP32 with no additional hardware (we wrote an Arduino library for that as well)
• Multiple units (up to 12 in current version) can send data to the same Arduino/ESP32
• Sends out detected muscle activity level, 4-bins spectrum and in nRF24 mode - also raw EMG data
• You can use it with a bracelet and dry electrodes, or solder/attach another connector and stick them via gel electrodes, if you need more precision

Specs

• Microcontroller: nRF52832 BLE SoC
• Op amp: AD8293, with additional bias compensation via firmware
• Mains noise filter: digital 50/60 Hz filter, auto detects mains frequency
• IMU: LSM6DSR gyroscope/accelerometer (low noise, 16-bit)
• Short circuit protection: yes; PTC resettable fuse
• Antenna type: chip antenna
• Antenna gain: 5 dB
• Charging: micro USB type C, with a separate LiPo charger
• Weight: 9 g (just the device with dry electrodes attached)

Order options

You can either order uMyo full kit with a bracelet, or just uMyo, or mix those two options. If you want 1 uMyo kit and also want to add some more separate uMyos, make sure to put them into cart one by one! You can also buy 2x or 3x devices kits. If you order several 1 device kits, we'll make sure to put them into separate boxes in case you need them separately for different people, for example. Otherwise, it's cheaper and easier to buy 2x and 3x kits if you need more than one uMyo.

Standard kit includes:

• 1 uMyo device
• bracelet of your color and size of choice
• 10x gel electrodes (22*22 mm)
• 2 sets of dry electrodes (1 + 1 replacement)
• 2 sets of wet electrode snap connectors (1 + 1 replacement)
• USB type C cable (for charging)
• lipo battery charger board
• CR2032 battery connector
• user manual

uMyo only includes:

• 1 uMyo device
• 2 sets of dry electrodes (1 + 1 replacement)
• 2 sets of wet electrode snap connectors (1 + 1 replacement)
• USB type C cable (for charging)
• CR2032 battery connector
• user manual

Bracelets: 25x380 (longer) option is for average and larger arms, 25x290 (shorter) is for smaller arms. Smaller arms are roughly the ones around 25 cm (10 inches) and down in circumference if you measure right below the elbow. If your circumference is over 25 cm, probably choose the 380 option. We didn't know how many bracelets to get of each color, so we're testing for now. We're very interested to see which ones you like! The smaller bracelets don't have orange color cause our supplier run out of them suddenly.

If you're adding into cart "Just uMyo" option, please also choose "No bracelet". If you forget to change it, don't worry, in this case we'll just not ship it. We can't change the bracelet options automatically depending on kit unfortunately, sorry for that :(

Looks like that's it. We're excited to see you test uMyo!