Q&A about Lightning Network node Ptarmigan and Lightning Shield for Arduino (for beginners)
Last Updated: 20 Jul 2021
The development of the Ptarmigan is in suspension.
After having released the mainnet of Lightning Network node called Ptarmigan at the end of April, we have been asked questions about Ptarmigan. Also, we are offering 100 Lightning Shields for Arduino to developers (for the cost of parts!) for enabling them to enjoy prototyping with LN, but there are also a few unclear points. In this article, on behalf of Nayuta I am making them as much clear as possible.
If you have additional questions, please contact me and feel free to ask!
About Ptarmigan
Q1. How do you pronounce Ptarmigan?
A1. That is /ˈtɑːmɪɡən/. It means “Thunderbird” in Japanese. All the names of Nayuta’s projects are the names of birds such as a hawk, eagle, swallow, kingfisher, and ptarmigan.
Q2. What is Ptarmigan and its features?
A2. Ptarmigan is software with Lightning Network (BOLT) specifications. The goal is to establish LN software with the ability to operate on small hardware in the long-run. We think Ptarmigan is the smallest footprint software in the other major implementation; c-lightning, eclair, and lnd, although we are not sure how to appropriately compare softwares footprints because it depends on how to be compiled. Instead of the small footprint, however, Ptarmigan’s throughput is a little bit lower so far.
For more information about Ptarmigan and its development background, please see the following article by our CEO Kenichi Kurimoto.
About Lightning Shield for Arduino
Q3. What is Lightning Shield for Arduino?
A3. Lightning Shield is a connection board that allows developers to use LN features from Arduino. If you want to make a prototype using LN, you only need to write the program for Arduino. Even anyone unfamiliar with embedded development can make it easily!
Although Lightning Shield is originally named by us, a field of Arduino Shield exists in general. Arduino Shield is a variety of expansion boards that are stacked to add various features to an electrical handicraft.
Q4. Why do you offer the shield?
A4. The key here is to make a lot of prototypes. So far, nobody has known what is a killer app for LoT (Lightning Network × IoT), while some of them have high hopes in the field.
This project has two purposes. One is to increase developers who are not experts in LN but are able to use LN. There is no need to set up a node in the cloud because RasPiZero has the independent node Ptarmigan. The other is to get development experts to make their prototypes many times. The prototypes may give you a hopeful clue for the future product.
Q5. How does Lightning Shield work in the following demo video?
A5.
Firstly, three boards appear in the video — Rasberry Pi Zero W, Arduino UNO, and Lightning Shield for Arduino.
Each functions are the following:
・Raspberry Pi controls Lightning Network. Ptarmigan uses Raspberry Pi Zero W. Instead of the poorest spec, it runs LN without connecting to external storage. The full node bitcoind requires a lot of disk space and RAM, so Raspberry Pi Zero W has no power to operate. Therefore, Lightning Shield gets it to work by using SPV instead of bitcoind. It will achieve small size and low power consumption, however, it will slow down and take about 4–8 seconds for receipt of Bitcoin.
・Arduino activates User’s Shield (see the image below) and triggers Lightning Shield to enable to use LN.
・About Lightning Shield, please refer to Q&A3.
For example, you have made a vending machine by yourself.
- A consumer presses a button of drink he/she wants to get.
= A consumer presses the button put on your Shield (User’s Shield in the above image).
2．He/She has to make a Lightning payment.
= After the program recognizes that the button is pressed, Arduino requests to create an invoice to Lightning Shield, and then Lightning Shield shows QR code on the ePaper.
3．He/She pays and gets the drink.
= Arduino receives the notification about the receipt of LN from Lightning Shield, and then Arduino controls your Shield to give him/her the drink.
Let me show you how it works in the following “snack vending machine” demo video.
Q6. Who is Lightning Shield offered for?
A6. For those who want to use LN for their Shield. Also, it is for an understanding person about Ptarmigan’s stabilization. So far Ptarmigan is a “Reckless version”, which contains bugs. Therefore, we expect users to spend only a small amount.
Now, Give it a try!
1. Please go to Nayuta Lightning shop to get the Lightning Shield.
2. Check the items that you can get at the shop. If you do not have not-included items, please prepare them by yourself.
・Included items: Lightning Shield for Arduino and 2.7inch E-Ink raw display
・Not included: Arduino UNO body, Raspberry Pi Zero W body/SD card, and connector to the Lightning Shield
3. After the Lightning Shield arrives, please read through here.
4. Now, enjoy making your LN electrical handicraft!
