https://github.com/ldab/wimb
Where is my Bike - IoT project based on u-blox GNSS and NB-IoT modules
https://github.com/ldab/wimb
arduino gnss gps iot lte-m nb-iot samd21 u-blox
Last synced: 3 months ago
JSON representation
Where is my Bike - IoT project based on u-blox GNSS and NB-IoT modules
- Host: GitHub
- URL: https://github.com/ldab/wimb
- Owner: ldab
- License: gpl-3.0
- Created: 2019-02-02T14:23:46.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2019-05-05T20:34:54.000Z (about 6 years ago)
- Last Synced: 2025-02-17T17:44:54.320Z (3 months ago)
- Topics: arduino, gnss, gps, iot, lte-m, nb-iot, samd21, u-blox
- Language: C++
- Homepage:
- Size: 29.7 MB
- Stars: 2
- Watchers: 4
- Forks: 2
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# WimB - Where is my Bike
The firmware has been writen using PlatformIO which is a nice, neat IDE, check it out: Learn how to install PlatformIO IDE
[](https://github.com/ldab/wimb/releases/latest)
[](https://travis-ci.org/ldab/WimB)
[](https://github.com/ldab/wimb/blob/master/LICENSE)
## Download Blynk App: [Getting Started with Blynk](https://www.blynk.cc/getting-started/)
This is a minimalist Blynk App you will **1,800 energy points**.
* Download Blynk App: [](http://j.mp/blynk_Android) [](http://j.mp/blynk_iOS)
* Touch the QR-code icon and point the camera to the code below
* Enjoy my app!
## Content
1. [TODO](/README.md#TODO)
2. [How does it work?](/README.md#how-does-it-work)
3. [Estimated Power Consumption](/README.md#Estimated-Power-Consumption)
4. [Cellular data usage](/README.md#cellular-data-usage)
5. [SARA-R4 PWR_ON Pin](/README.md#SARA-R4-PWR_ON-Pin)
6. [SARA-R4 PSM - Power Save Mode configuration](/README.md#sara-r4-psm---power-save-mode-configuration)
7. [SERCOM and PIN mapping](/README.md#SERCOM-and-PIN-mapping)
8. [Schematic](/README.md#schematic)
9. [DataSheets](/README.md#datasheets)
10. [Enclosure](/README.md#enclosure)
11. [How to Start?](/README.md#how-to-start)
12. [Credits](/README.md#credits)
## TODO
- [x] Put device to sleep;
- [ ] Communnicate with SARA-R4
- [x] Set SARA-PSM values
- [ ] Communicate with GNSS;
- [ ] AssistNow AID for GNSS
- [x] Set interrupts on accelerometer;
- [x] Finish accelerometer lib
- [ ] Monitor SARA GPIO in order to detect modem is ready +UGPIOC
- [ ] Monitor SARA V_INT in order to detect modem ON
- [ ] Monitor GNSS *something* in order to detect GNSS awake
## How does it work?
Here you will find a simplified flowchart demonstrating how the code works:
## Estimated Power Consumption
This is hard to predict however we have the [Datasheets](./datasheet) and can roughly estimate it, we have:
* ATSAMD21E18 MCU;
* SARA-R412;
* SAM-M8Q;
* LIS3DH IMU;
* TXS0102 Level-shifter;
* SN74LVC1G07 Level-shifter;
* HT7833 LDO;
* TP4056 Battery charger;
* Battery ADC;
#### Low power - Sleeping
Arduino library set all pins as `INPUT` on `wiring.c` this result in excessive current draw, I got around 300μA on the best case scenario, turning all Clock off, VREG, and BOD33.
```
// Setup all pins (digital and analog) in INPUT mode (default is nothing)
for (uint32_t ul = 0 ; ul < NUM_DIGITAL_PINS ; ul++ )
{
pinMode( ul, INPUT ) ;
}
```
it we change SWCLK & SWDIO to `pinMode( ul, INPUT_PULLUP ) ;` **BOOM** -> board current on sleep was spot on 48μA.
Component | ~TYP μA
------------------------- | ------
ATSAMD21E18 MCU | 4
SARA-R412 | 6
SAM-M8Q | 15
LIS3DH IMU | 2
TXS0102 Level-shifter | 2
SN74LVC1G07 Level-shifter | 5
HT7833 LDO | Assume 10
TP4056 Battery charger | 2
Battery ADC | 2
TOTAL | 48
#### Tracking
Component | ~TYP μA
------------------------- | ------
ATSAMD21E18 MCU | 4,000
SARA-R412 | 27,200*
SAM-M8Q | 9,500
LIS3DH IMU | 2
TXS0102 Level-shifter | 14
SN74LVC1G07 Level-shifter | 5
HT7833 LDO | Assume 10
TP4056 Battery charger | 2
Battery ADC | 2
TOTAL | ~41mA
*Current for Modem depends on the update interval, registration and signal level -> 200mA max for TX/RX @30sec to exec every 300 sec + 9mA @Active mode = 27.2mA
## Cellular data usage
[Blynk Protocol message](https://github.com/blynkkk/blynk-server/blob/master/docs/README_FOR_APP_DEVS.md#protocol-messages)
* [Blynk HEARTBEAT](https://community.blynk.cc/t/expected-data-usage-for-hardware-connection-heartbeat-to-blynk-server/7138/16) = 5 bytes every minute;
* [Button message](https://community.blynk.cc/t/solved-gsm-data-usage/16122/2?u=ldb) = ~10 bytes
* [Data message](https://community.blynk.cc/t/blynk-electron-data-usage-extremely-high/16577/4?u=ldb) = ~14 bytes
* [TCP Overhead?](https://community.blynk.cc/t/expected-data-usage-for-hardware-connection-heartbeat-to-blynk-server/7138/16) = 20 bytes
If it connects twice a day non-active => ( Clear Map + Active? + Update Battery ) * 2 = bump it up to 80 bytes/day
Active mode running at 300 seconds => ( 5 * Heartbeat + Active? + Update Battery + Send location )* 12 = 800 bytes/hour
## SARA-R4 PWR_ON Pin
Low level on the PWR_ON pin, which is normally set high by an internal pull-up, for a valid time period when the applied VCCvoltage is within the valid operating range. The PWR_ON line has to be driven by open drain, open collector or contact switch
Parameter |Min. |Max. |Unit|Remarks
--------------- | --- |----- | -- | ---------------------------------------
PWR_ON low time |0.15 | 3.20 | s | Low time to trigger module switch *ON*
PWR_ON low time |1.5 | | s | Low time to trigger module switch *OFF*
## SARA-R4 PSM - Power Save Mode configuration
The grant of PSM is a negotiation between SARA-R4/N4 series module and the **attached network:** the network accepts PSM by providing the actual value of the “Active Timer” (and “Periodic Update Timer”) to be used in the Attach/TAU/RAU accept procedure. The maximum duration, including the “Periodic Update Timer”, is about 413 days. The SARA-R4/N4 series module enters PSM low power deep sleep mode only after the “Active Timer” expires
* If the power saving mode is enabled (+CPSMS: 1), everything on the device will power down except thereal-time clock (RTC) after the expiry of T3324 (Active Time). It will stay powered down until the expiry ofT3412 (Extended TAU Timer) or if the Power On line is toggled.
* If the power saving mode is disabled (+CPSMS: 0), the device will not enter Power Save Mode (PSM)
#### Requested_Periodic_TAU - PSM total duration
```
Bits 5 to 1 represent the binary coded timer value.
Bits 6 to 8 defines the timer value unit for the GPRS timer:
8 7 6
0 0 0 value is incremented in multiples of 10 minutes
0 0 1 value is incremented in multiples of 1 hour
0 1 0 value is incremented in multiples of 10 hours
0 1 1 value is incremented in multiples of 2 seconds
1 0 0 value is incremented in multiples of 30 seconds
1 0 1 value is incremented in multiples of 1 minute
1 1 0 value is incremented in multiples of 320 hours
1 1 1 value indicates that the timer is deactivated.
```
**The requested extended periodic TAU value(T3412) iscoded as one byte (octet 3) of the GPRS Timer 3 information element coded as bitformat (e.g. "10100001" equals 1 minute). see the GPRS Timer 3 IE in 3GPP TS 24.008 Table10.5.163a/3GPP TS 24.008 - page 669**
#### Requested_Active_Time - Active/Paging time
```
Bits 5 to 1 represent the binary coded timer value.
Bits 6 to 8 defines the timer value unit for the GPRS timer as follows:
Bits
8 7 6
0 0 0 value is incremented in multiples of 2 seconds
0 0 1 value is incremented in multiples of 1 minute
0 1 0 value is incremented in multiples of decihours
1 1 1 value indicates that the timer is deactivated.
Other values shall be interpreted as multiples of 1 minute in this version of the protocol.
```
**Requested Active Time value (T3324) iscoded as one byte (octet 3) of the GPRS Timer 2 information element coded as bitformat (e.g. "00100100" equals 4 minutes). see the GPRS Timer 2 IE in 3GPP TS 24.008 Table10.5.163/3GPP TS 24.008 - page 668**
## SERCOM and PIN mapping
PIN mapping and re-assignment are required since we need 3x UART and unfortunatelly Adafruit Trinket M0 did not use the same combination as we needed/wanted.
Those changes are made on the `variant.h` and `variant.cpp` found on your installation directory `.platformio\packages\framework-arduinosam\variants\trinket_m0`.
On the `.cpp` file we comment the `Serial1` definition as `SERCOM0` will be used by the I2C interface:
https://github.com/ldab/WimB/blob/5da6a90e527ac1eb7648ca4fd2846885c14b10b4/board_variant/variant.cpp#L97-L102
The `.h` file we define `SERCOM0` as the interface for I2C, as well different PIN because of `SERCOM` and `SERCOM_ALT` definition
https://github.com/ldab/WimB/blob/5da6a90e527ac1eb7648ca4fd2846885c14b10b4/board_variant/variant.h#L142-L145
## Schematic
* The Schematics provided here are provided "as it is" and no guarantee is given as it does not follow the supplier specifications especially on the antenna design:
## Datasheets
You can find technical information here: [datasheets](./datasheet)
## Enclosure
A 3D print file for the enclosure is also available (untestest/not printed) [here](./3DPrint%20Enclosure).
## How to start?
## Credits
Github Shields and Badges created with [Shields.io](https://github.com/badges/shields/)
Flowchart made with [VISME](https://www.visme.co/)
3D Design inspired by [Adafruit Youtube video](https://www.youtube.com/watch?v=VVmOtM60VWw) using [Autodesk Fusin 360](https://www.autodesk.com/products/fusion-360/overview)
Icons made by [Smashicons](https://www.flaticon.com/authors/smashicons) from [Flaticon](www.flaticon.com) is licensed by Creative Commons BY 3.0 [CC BY 3.0](https://creativecommons.org/licenses/by/3.0/)