Pycom SiPy Overview

Updated 11 April 2018

If there’s an odd one in the Pycom family of microprocessor boards it’s this one, the SiPy. There’s nothing wrong with it, it’s just that its sister board the LoPy4 has the same capabilities as SiPy, plus a LoRa radio, for the same money.

SiPy gets its name from the inclusion of a Sigfox radio. Otherwise it has all the amazing capabilities of any of the Pycom microcontroller boards. Have a look at our overview of the WiPy for more on the extensive features of all the Pycom devices.

What is Sigfox?

Sigfox Logo
The Sigfox logo

Sigfox is designed to be an entire device-to-cloud communications system. Sigfox radios are built into devices and connect to the Internet through a Sigfox Operator network. Yes, there’s a subscription cost for access to the Sigfox network but it’s small when compared to, say, a cellular data service. Pycom Sigfox devices come with 2 years of connectivity free!

Sigfox is:

  • A Low Power Wide Area Network (LPWAN) radio that’s built into devices
  • A network protocol stack for communications between devices and the Sigfox network
  • A low-cost network access service through the global Sigfox Operator network
  • Cloud management services that interface between the Sigfox network and your IoT back-end system.

It’s designed for:

  • Secure communication
  • Low power consumption
  • Long-range communications (up to 50km!)
  • Low cost-per-device network access
  • Single-hop transmission with base stations providing connectivity
  • A global standard: any device, any country
  • Scalability to millions and billions of devices

If I said “Sigfox is like LoRa, but different” it wouldn’t be fair to Sigfox. Yes, Sigfox and LoRa use the same radio frequencies (ISM band) and are designed to be Internet of Things (IoT) communications systems, but Sigfox is much more than that.

Imagine you have an internet of things product, like a smart water meter or something. How would it connect to the Internet? Bluetooth has a short range so there’s no such thing as a Bluetooth Internet service provider. WiFi is available at many locations but each is privately owned. Cellular data is widely available but expensive and various systems exist globally.

Sigfox is already deployed globally and exists to serve IoT devices. You can check the global coverage map to see which areas are already served by the Sigfox Operator network. Scroll down the same page to see all the Sigfox Operators by country. Do you want to deploy devices to an area currently outside the coverage? Sigfox Operators can supply base stations on demand through “coverage as a service” agreements.

Sigfox Network Topology
Sigfox network architecture

Now before your mind races off thinking about broadband IoT with over-the-air software updates and other bandwidth intensive applications I have some bad news. IoT, pure IoT, is about low-power devices. We’re talking about devices that can run for years on a small battery while still connecting to the Internet when necessary. Sigfox, like other low-power wide area network (LPWAN) technologies, limits transmit and receive operations. This partly owes to the need to conserve battery power, but the ISM radio band also puts restrictions on how much “air time” each device gets per hour.

Are you ready for this? A message sent from device to network (uplink) is 0, 4, 8 or 12 bytes! A downlink message is always 8 bytes and must be requested by the device! There’s also a limit of 140 messages per day (6 uplinks per hour and 4 downlinks per day. Source). This looks like it’s not enough to do anything worthwhile, but it is.

Going back to the smart water meter example. If a city decided to deploy these, they could ensure the entire city has Sigfox coverage and install smart meters at every property. The meters would only need to transmit their current reading on a fixed interval and so could be “asleep” most of the time, conserving power and running on a single battery for years.

Imagine a farmer wants to trial smart-watering of crops. Battery-powered soil moisture probes with Sigfox radios could wake once every day, read the soil moisture and uplink the data to a cloud service. The cloud service would blend soil moisture data and rain forecasts to decide which water pumps to run and which solenoids to open. Every day the IoT device in charge of the water pumps could downlink the length of time to run water on each area to control the pumps and solenoids. The system then becomes closed-loop as the effectiveness of the watering schedule is directly measured by the soil moisture probes.

There are also many applications that could use the included two years of Sigfox connectivity to do some one-off project. Smart geocaching anyone?

Features

SiPy Features
SiPy features

Of course all the great standard features of Pycom microcontrollers are there. WiFi and Bluetooth with a built-in antenna. Dual core processor, hardware floating point support, lots of GPIOs, two UARTs, I2C, I2S, and on and on. Click the SiPy features image above for all the details!

Sigfox as used in Australia, New Zealand and South America is called RCZ4. The SiPy needs only 24mA when downlinking a message, and 257mA during uplink. When in sleep mode it consumes only 0.5uA.

Pycom SiPy Pinout Diagram
SiPy pinout diagram

Have a question? Ask the Author of this guide today!

Please enter minimum 20 characters

Your comment will be posted (automatically) on our Support Forum which is publicly accessible. Don't enter private information, such as your phone number.

Expect a quick reply during business hours, many of us check-in over the weekend as well.

Comments


Loading...
Feedback

Please continue if you would like to leave feedback for any of these topics:

  • Website features/issues
  • Content errors/improvements
  • Missing products/categories
  • Product assignments to categories
  • Search results relevance

For all other inquiries (orders status, stock levels, etc), please contact our support team for quick assistance.

Note: click continue and a draft email will be opened to edit. If you don't have an email client on your device, then send a message via the chat icon on the bottom left of our website.

Makers love reviews as much as you do, please follow this link to review the products you have purchased.