Mercury project version (in progress)

[dav1248]

Preliminary version of simple-spectro eagle file for the purpose of the Mercury Project in Univalle, Cali.

Changes

• adding of voltage inverter TPS60400 for UV LED
• adding of digital potentiometer MCP4452, liberated pins A0/A1 for GPRS communication
• adding of I2C (RJ12) connector
• adding of (temporary) connector for LED and light to freq. converter for Bioreactor
• Replacing of SCL/SDA by A2/A4 on MC pins to free SCL/SDA for I2C slave connection
• adding of SIM800L module (linked VBAT1 with pin of SIM800L, moved screen brightness adjuster and its caps)

Remarques:

• nets A0/A1 not routed
• nets D12/HWB not routed

Questions

• Y a-t-il besoin de libérer un pin supplémentaire sur le MC pour le reset du module GPRS?
• Peut-on utiliser des pins Analog (A0, A1) comme software serial comm. avec le module GPRS?
• Est-ce OK de connecter le 5V de la connection I2C slave à VUSB?
• A quoi connecter GND1 et GND 2 (toujours pour I2C)?
• Quelles valeurs pour condensateurs de l'inverseur de voltage?

[lpatiny]

sim800L:

• A0 and A1 should be ok for software serial
• RST if there is a pin available would be nice. Othewise should be forced either to VCC or GND depending specifications
• Should be powered by VBAT

Other:

• 5V I2 should go through a Schottky like for the Vusb
• I2C GND 1 and 2 should go to GND
• capacity for inverter should be the one from the specifications (1u)

[lpatiny]

It seems to me it will be easier to replace the quad digital pot by MCP4728. This component is internally protected and allows to give up to 10mA. Not obvious for the quad pot.

[lpatiny]

• When connecting to GND just create a via. No need to make long traces and many of them (also existing one) should be shortened.
• On the front side please try to create a VCC plane in order also to reduce the number of traces
• Please also try to add Possibility to add a 430 nm UV led instead of RGB #78 It would be connected like the blue led of the RGB but connected to -3.3V. It should have its own resistor (default 1k)
• Add a resistor to the UV led, default 100 Ohms

[lpatiny]

For external led connection may we should also use RJ12. They are small, relatively reliable and very cheap. We would have 6 wires.

• R / G / B
• GND / VCC
• counter

For pin mapping we could have:

• counter
• VCC
• GND
• R
• G
• B

[lpatiny]

Names of wire on SIM800 connector should corresponds to a name of the microcontroller

[lpatiny]

RJ12 connector and connector for external led should be on the other face

[lpatiny]

Could move all those components higher to have more room for sim800l

[dav1248]

Question pour le connecteur bioréacteur :
Actuellement, il y a 7 fils qui partent de la carte pour le plongeur :

• 2 pour la LED UV (dont GND)
• 2 pour la LED RGB (rouge + GND)
• 3 pour le capteur (GND + D12 + HWB)
  Faut-il changer cela du coup ?

[lpatiny]

Il faut leur demander mais oui je le changerais. Il faut qu'un GND de toutes façons. La LED RGB externe pourrait avoir ses propres résistances éventuellement ce qui donnerait un peu plus de flexibilité

[dav1248]

first correction

• RST pin of SIM800L connected to VCC following specifications
• Added a Schottky for 5V I2C
• Replaced digipot by MCP4728
• Created a VCC plane on back (blue) side
• added Possibility to add a 430 nm UV led instead of RGB #78
• added default 100ohm resistor to UV led
• added bioreactor RJ12 connector

Info: SIM800L is on the same side as the LCD. it is placed so to easily insert and remove a SIM card for field use.