'******************************************************
' MM DISCHARGER
' Universal discharger for rechargeable batteries v046
' (1 or 7 cells NiCd, NiMH or 1 cell Li-Ion 18650)
'
' Easily to convert into a 4 day data logger
' (because of its self-scaling capability 1 min - 4 days)
'
' System: MMBasic 4.7 (b32)
' Micromite 2 (PIC32MX170/28, Micks BP170 + 2.4" TFT)
' by twofingers 11-2015 at TBS
'
' -----------------------------------------------------
' Uses a ILI9341 TFT and/or serial monitor (vt100).
' Automatic discharger resistor selection, self-scaling.
'------------------------------------------------------
' Purpose:
' The measurement of the capacity of rechargeable batteries.
' This program discharges one rechargeable battery
' (NiMH, LiIon 18650) to measure its capacitance. Results (mAh)
' and the discharge curve are shown on the TFT.
'
' You can also use a log file with a serial monitor (eg TT)
' and import it in Excel.
'
' !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
' Note/Warning:
' Frequent discharge can/will
' shorten rechargeable batteries life!
' Any cell has a limited lifecycle.
' !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
' For comparison:
' A noname alkaline battery has 505mAh.
'
'******************************************************
'
' Used PINs (MX170/28):
' 23 as Input
' 16 as Output
' 17 as Output
' 18 as Output
'
'*******************************************************
' This code may be freely distributed and changed.
' Provided AS IS without any warranty.
' Use it at your own risk. All information is provided for
' educational purposes only!
' ------------------------------------------------------
' ++++++ Credit to Geoff for his great MMBasic ++++++
'*******************************************************
'
' This is the schematic example for a simple 9V discharger:
'
' A IN
' o-----------+ o---------------o----------+
' | | | |
' | .-. Disch.R .-. |
' | | | 470R R3 | | |
' <- MM2 | | | R2 820k| | |
' | '-' '-' |
' | | | |
' | | | | Battery
' +---------))--------------+----+ |
' D OUT | | | ---
' o--------o------+ D| | | -
' | | ||-| N-MOSFET | | |
' | | ||<) IRLML2502 | --- |
' .-. +--||-| T1 .-. --- |
' R1 | | G S| R4 | | | C1 |
' 100k | | | 100k | | | 100n|
' '-' | '-' | |
' | | | | |
' o--------o------------o---------------o----o-----+
' GnD
'
'
' Recomended values (R2):
' 1.2V NiMH 1500-2500mA: C/10 = 200mA = 4,7R/Threshold: 1V
' 3.6V LiIon 2000-3000mA: C/10 = 200mA = 18R /Threshold: 3V
' 9V NiMH 150-250mA: C/10 = 20mA = 470R/Threshold: 7V
'--------------------------------------------
'
' (3x) R1=100K, 1/8W
' (3x) R2a=470R, 1/4W (b=18R, 1W, c=4.7R, 1/2W)
' R3=820k, 1/8W
' R4=100k, 1/8W
'
' C1=~100n
' (3x) T1=N-MosFet, logic level (IRL540, IRLML2502, ...)
' voltage drop on T1 = 1.3mV
'
' see ->>MMDIS.JPG for the real thing
'------------------------------------------
' Command line settings for TFT Display
' OPTION LCDPANEL ILI9341, L, 4, 5, 6
' OPTION TOUCH 7, 2
' GUI TEST TOUCH
' GUI CALIBRATE
'-----------------------------------------