20th Anniversary

20th Anniversary of the
OSHONSOFT PROJECT
(2001 - 2021)

Intelligent NiCd/NiMH Charger/Cycler with 2x16 Character LCD

The accu cycler project presented here is a great solution for charging and discharging NiCd and NiMH accumulators for R/C modelers and others who make use of these accumulator types. With its performance it is very close to the many of the commercial products available on the market. The 'power' part of the design is not a common choice in similar applications, having in mind of its size and energy dissipation, but it is very easy to understand its principles of operation even for beginners in electronics. The 'intelligent' part of the design communicates with PC using serial port providing additional process visualization. The process graph is saved to on-board EEPROM memory and it is possible to download the data to PC even when the charging/discharging process has finished.

The screenshot of the Accu Cycler application:

The Accu Cycler application is available for the download here.

The firmware for the 16F876A chip used in this design is given in the form of Basic source program that has to be compiled with PIC Simulator IDE integrated Basic compiler to get the HEX file ready to be programmed into the microcontroller.

The firmware code (16F876A):

#define CONF_WORD = 0x3f72
#define CLOCK_FREQUENCY = 12

Symbol t_right = PORTB.3
Symbol t_down = PORTB.2
Symbol t_up = PORTB.1
Symbol t_left = PORTB.0
Symbol ledcharge = PORTA.1
Symbol leddischarge = PORTA.5
Symbol charge = PORTC.2
Symbol discharge = PORTC.1
Symbol i2cclock = PORTC.3
Symbol i2cdata = PORTC.4

#define LCD_BITS = 4
#define LCD_DREG = PORTB
#define LCD_DBIT = 4
#define LCD_RSREG = PORTC
#define LCD_RSBIT = 0
#define LCD_EREG = PORTC
#define LCD_EBIT = 5

Const c_right = 1
Const c_up = 2
Const c_down = 3
Const c_left = 4

Dim vin As Word
Dim i As Byte
Dim j As Byte
Dim an0 As Word
Dim vmod As Word
Dim vfinal As Word

Dim v(13) As Word
Dim vmax As Word
Dim vmaxdelay As Byte
Dim vmaxnum As Byte

Dim finish As Bit
Dim address As Word
Dim seconds As Byte
Dim minutes As Word
Dim hours As Byte

Dim voltage As Word
Dim voltage1 As Word
Dim voltage2 As Word
Dim cnt As Word
Dim sample As Word

Dim program As Byte
Dim phase As Byte
Dim key As Byte

Dim dischargelimit As Word
Dim signalfiltertype As Byte
Dim peakgap As Byte
Dim peakdetect As Byte
Dim mintime As Byte
Dim minvalue As Word
Dim maxtime As Word

PORTA = 0
PORTB = 0
PORTC = 0
TRISA.1 = 0
TRISA.5 = 0
TRISC.2 = 0
TRISC.1 = 0
All_Digital
ADCON1 = 0x0f
UART_Init 19200
Lcdinit
WaitMs 1000

Gosub loadparameters

newprogram:
Gosub welcome
Gosub selectprogram
If program = 1 Then Gosub prog_charge
If program = 2 Then Gosub prog_discharge
If program = 3 Then Goto prog_cycle
If program = 4 Then Goto prog_setup
If program = 5 Then Gosub prog_setupdefaults
If program = 6 Then Goto prog_memory
Goto newprogram
End

welcome:
Lcdcmdout LcdClear
Lcdout "OshonSoft Cycler"
Lcdcmdout LcdLine2Home
Lcdout "Initializing..."
WaitMs 3000
Return

selectprogram:
phase = 1
Lcdcmdout LcdClear
Lcdout "Select Program:"
loop1:
Lcdcmdout LcdLine2Clear
If phase = 1 Then Lcdout "1-Charge"
If phase = 2 Then Lcdout "2-Discharge"
If phase = 3 Then Lcdout "3-Cycle"
If phase = 4 Then Lcdout "4-Setup"
If phase = 5 Then Lcdout "5-Setup defaults"
If phase = 6 Then Lcdout "6-Memory"
Gosub waitkey
If key = c_down Then
	phase = phase + 1
	If phase = 7 Then phase = 1
	Goto loop1
Endif
If key = c_up Then
	phase = phase - 1
	If phase = 0 Then phase = 6
	Goto loop1
Endif
If key = c_right Then program = phase
If key = c_left Then program = 0
Return

waitkey:
key = 0
If t_right = 1 Then key = c_right
If t_up = 1 Then key = c_up
If t_down = 1 Then key = c_down
If t_left = 1 Then key = c_left
If key = 0 Then Goto waitkey
Gosub debounce
Return

getkey:
key = 0
If t_right = 1 Then key = c_right
If t_up = 1 Then key = c_up
If t_down = 1 Then key = c_down
If t_left = 1 Then key = c_left
If key > 0 Then Gosub debounce
Return

debounce:
If t_right = 1 Then i = 0
If t_up = 1 Then i = 0
If t_down = 1 Then i = 0
If t_left = 1 Then i = 0
i = i + 1
WaitMs 10
If i < 10 Then Goto debounce
Return

scankey:
If t_right = 1 Then key = c_right
If t_up = 1 Then key = c_up
If t_down = 1 Then key = c_down
If t_left = 1 Then key = c_left
Return

initroutine:
Lcdcmdout LcdClear
Lcdout "Starting..."
WaitMs 3000
Gosub getvin
For i = 1 To 12
	v(i) = vin
Next i
vmax = 0
vmaxdelay = 0
vmaxnum = 0
finish = 0
address = 0
seconds = 251
minutes = 0
hours = 0
key = 0
Lcdcmdout LcdClear
Return

prog_discharge:
discharge = 1
leddischarge = 1
Gosub initroutine
Lcdout "Discharging..."
Lcdcmdout LcdLine2Home
While finish = 0
	If signalfiltertype = 1 Then Gosub getvfinal1
	If signalfiltertype = 2 Then Gosub getvfinal2
	If signalfiltertype = 3 Then Gosub getvfinal3
	If vfinal <= dischargelimit Then finish = 1
	Gosub settime
	Gosub showvoltage
	Gosub storeeeprom
	Gosub serialroutine
	If key = c_left Then finish = 1
	key = 0
Wend
Lcdcmdout LcdLine1Clear
Lcdout "Completed!"
discharge = 0
leddischarge = 0
Gosub endroutine
WaitMs 3000
Return

prog_charge:
charge = 1
ledcharge = 1
Gosub initroutine
Lcdout "Charging..."
Lcdcmdout LcdLine2Home
While finish = 0
	If signalfiltertype = 1 Then Gosub getvfinal1
	If signalfiltertype = 2 Then Gosub getvfinal2
	If signalfiltertype = 3 Then Gosub getvfinal3
	If vfinal > vmax Then vmaxdelay = vmaxdelay + 1
	If vmaxdelay = 5 Then
		If vmaxnum < 5 Then vmaxnum = vmaxnum + 1
		vmax = vfinal
		vmaxdelay = 0
	Endif
	If peakdetect = 1 Then
		vfinal = vfinal + peakgap
		If vfinal <= vmax Then finish = 1
		vfinal = vfinal - peakgap
		If vmaxnum < 5 Then finish = 0
	Endif
	If minutes < mintime Then
		finish = 0
		vmax = vfinal
		vmaxdelay = 0
	Endif
	If vfinal < minvalue Then
		finish = 0
		vmax = vfinal
		vmaxdelay = 0
	Endif
	If minutes >= maxtime Then finish = 1
	Gosub settime
	Gosub showvoltage
	Gosub storeeeprom
	Gosub serialroutine
	If key = c_left Then finish = 1
	key = 0
Wend
Lcdcmdout LcdLine1Clear
Lcdout "Completed!"
charge = 0
ledcharge = 0
Gosub endroutine
WaitMs 3000
Return

prog_cycle:
Gosub prog_discharge
WaitMs 10000
Gosub prog_charge
Goto newprogram
Return

prog_setupdefaults:
dischargelimit = 290
signalfiltertype = 3
peakgap = 2
peakdetect = 1
mintime = 5
minvalue = 495
maxtime = 600
Gosub saveparameters
Return

prog_setup:
phase = 1
setuploop:
Lcdcmdout LcdClear
Lcdout "Setup Options:"
Lcdcmdout LcdLine2Clear
If phase = 1 Then Lcdout "1-DischargeLimit"
If phase = 2 Then Lcdout "2-FilterType"
If phase = 3 Then Lcdout "3-PeakGap"
If phase = 4 Then Lcdout "4-PeakDetect"
If phase = 5 Then Lcdout "5-MinTime"
If phase = 6 Then Lcdout "6-MinValue"
If phase = 7 Then Lcdout "7-MaxTime"
Gosub waitkey
If key = c_down Then
	phase = phase + 1
	If phase = 8 Then phase = 1
	Goto setuploop
Endif
If key = c_up Then
	phase = phase - 1
	If phase = 0 Then phase = 7
	Goto setuploop
Endif
If key = c_right Then
	If phase = 1 Then Gosub setup1
	If phase = 2 Then Gosub setup2
	If phase = 3 Then Gosub setup3
	If phase = 4 Then Gosub setup4
	If phase = 5 Then Gosub setup5
	If phase = 6 Then Gosub setup6
	If phase = 7 Then Gosub setup7
	Goto setuploop
Endif
If key = c_left Then Gosub saveparameters
Goto newprogram
Return

setup1:
Lcdcmdout LcdClear
Lcdout "DischargeLimit:"
Lcdcmdout LcdLine2Home
Lcdout #dischargelimit
Lcdout "   "
vfinal = dischargelimit
Gosub showvoltageonly
Gosub waitkey
If key = c_up Then
	If dischargelimit < 1000 Then dischargelimit = dischargelimit + 5 Else dischargelimit = 10
	Goto setup1
Endif
If key = c_down Then
	If dischargelimit > 10 Then dischargelimit = dischargelimit - 5 Else dischargelimit = 1000
	Goto setup1
Endif
Return

setup2:
Lcdcmdout LcdClear
Lcdout "FilterType:"
Lcdcmdout LcdLine2Home
Lcdout #signalfiltertype
Lcdout "   "
If signalfiltertype = 1 Then Lcdout "Raw values"
If signalfiltertype = 2 Then Lcdout "Average LO"
If signalfiltertype = 3 Then Lcdout "Average HI"
Gosub waitkey
If key = c_up Then
	If signalfiltertype < 3 Then signalfiltertype = signalfiltertype + 1
	Goto setup2
Endif
If key = c_down Then
	If signalfiltertype > 1 Then signalfiltertype = signalfiltertype - 1
	Goto setup2
Endif
Return

setup3:
Lcdcmdout LcdClear
Lcdout "PeakGap:"
Lcdcmdout LcdLine2Home
Lcdout #peakgap
Lcdout "   "
vfinal = peakgap
Gosub showvoltageonly
Gosub waitkey
If key = c_up Then
	If peakgap < 10 Then peakgap = peakgap + 1 Else peakgap = 1
	Goto setup3
Endif
If key = c_down Then
	If peakgap > 1 Then peakgap = peakgap - 1 Else peakgap = 10
	Goto setup3
Endif
Return

setup4:
Lcdcmdout LcdClear
Lcdout "PeakDetect:"
Lcdcmdout LcdLine2Home
Lcdout #peakdetect
Lcdout "   "
If peakdetect = 0 Then Lcdout "Off"
If peakdetect = 1 Then Lcdout "On "
Gosub waitkey
If key = c_up Then
	peakdetect = 1
	Goto setup4
Endif
If key = c_down Then
	peakdetect = 0
	Goto setup4
Endif
Return

setup5:
Lcdcmdout LcdClear
Lcdout "MinTime:"
Lcdcmdout LcdLine2Home
Lcdout #mintime, " min"
Gosub waitkey
If key = c_up Then
	If mintime < 60 Then mintime = mintime + 1 Else mintime = 1
	Goto setup5
Endif
If key = c_down Then
	If mintime > 1 Then mintime = mintime - 1 Else mintime = 60
	Goto setup5
Endif
Return

setup6:
Lcdcmdout LcdClear
Lcdout "MinValue:"
Lcdcmdout LcdLine2Home
Lcdout #minvalue
Lcdout "   "
vfinal = minvalue
Gosub showvoltageonly
Gosub waitkey
If key = c_up Then
	If minvalue < 1000 Then minvalue = minvalue + 5 Else minvalue = 10
	Goto setup6
Endif
If key = c_down Then
	If minvalue > 10 Then minvalue = minvalue - 5 Else minvalue = 1000
	Goto setup6
Endif
Return

setup7:
Lcdcmdout LcdClear
Lcdout "MaxTime:"
Lcdcmdout LcdLine2Home
Lcdout #maxtime, " min"
Gosub waitkey
If key = c_up Then
	If maxtime < 1000 Then maxtime = maxtime + 5 Else maxtime = 10
	Goto setup7
Endif
If key = c_down Then
	If maxtime > 10 Then maxtime = maxtime - 5 Else maxtime = 1000
	Goto setup7
Endif
Return

loadparameters:
address = 30000
I2CRead i2cdata, i2cclock, 0xa0, address, dischargelimit.LB, dischargelimit.HB
address = 30002
I2CRead i2cdata, i2cclock, 0xa0, address, signalfiltertype
address = 30003
I2CRead i2cdata, i2cclock, 0xa0, address, peakgap
address = 30004
I2CRead i2cdata, i2cclock, 0xa0, address, peakdetect
address = 30005
I2CRead i2cdata, i2cclock, 0xa0, address, mintime
address = 30006
I2CRead i2cdata, i2cclock, 0xa0, address, minvalue.LB, minvalue.HB
address = 30008
I2CRead i2cdata, i2cclock, 0xa0, address, maxtime.LB, maxtime.HB
If dischargelimit < 10 Then dischargelimit = 10
If dischargelimit > 1000 Then dischargelimit = 1000
If signalfiltertype < 1 Then signalfiltertype = 1
If signalfiltertype > 3 Then signalfiltertype = 3
If peakgap < 1 Then peakgap = 1
If peakgap > 10 Then peakgap = 10
If peakdetect > 1 Then peakdetect = 1
If mintime < 1 Then mintime = 1
If mintime > 60 Then mintime = 60
If minvalue < 10 Then minvalue = 10
If minvalue > 1000 Then minvalue = 1000
If maxtime < 10 Then maxtime = 10
If maxtime > 1000 Then maxtime = 1000
Return

saveparameters:
address = 30000
I2CWrite i2cdata, i2cclock, 0xa0, address, dischargelimit.LB, dischargelimit.HB
WaitMs 20
address = 30002
I2CWrite i2cdata, i2cclock, 0xa0, address, signalfiltertype
WaitMs 20
address = 30003
I2CWrite i2cdata, i2cclock, 0xa0, address, peakgap
WaitMs 20
address = 30004
I2CWrite i2cdata, i2cclock, 0xa0, address, peakdetect
WaitMs 20
address = 30005
I2CWrite i2cdata, i2cclock, 0xa0, address, mintime
WaitMs 20
address = 30006
I2CWrite i2cdata, i2cclock, 0xa0, address, minvalue.LB, minvalue.HB
WaitMs 20
address = 30008
I2CWrite i2cdata, i2cclock, 0xa0, address, maxtime.LB, maxtime.HB
WaitMs 20
Return

getvin:
vin = 0
For i = 1 To 60
	ADC_Read 0, an0
	vin = vin + an0
	Gosub scankey
	WaitMs 83
Next i
vmod = vin Mod 60
vin = vin / 60
If vmod >= 30 Then vin = vin + 1
Return

getvfinal1:
Gosub getvin
vfinal = vin
Return

getvfinal2:
For i = 1 To 5
	j = i + 1
	v(i) = v(j)
Next i
Gosub getvin
v(6) = vin
vfinal = 0
For i = 1 To 6
	vfinal = vfinal + v(i)
Next i
vmod = vfinal Mod 6
vfinal = vfinal / 6
If vmod >= 3 Then vfinal = vfinal + 1
Return

getvfinal3:
For i = 1 To 11
	j = i + 1
	v(i) = v(j)
Next i
Gosub getvin
v(12) = vin
vfinal = 0
For i = 1 To 12
	vfinal = vfinal + v(i)
Next i
vmod = vfinal Mod 12
vfinal = vfinal / 12
If vmod >= 6 Then vfinal = vfinal + 1
Return

showvoltage:
'0V=0  2.5V=1023  2500/1023=2.444
voltage = (vfinal * 2) + (vfinal * 4 / 10)
voltage = voltage + (vfinal * 4 / 100) + (vfinal * 4 / 1000)
voltage1 = voltage / 1000
voltage2 = voltage Mod 1000
Lcdcmdout LcdLine2Clear
Lcdout #voltage1, "."
If voltage2 < 100 Then Lcdout "0"
If voltage2 < 10 Then Lcdout "0"
Lcdout #voltage2, "V  "
hours = minutes / 60
If hours < 10 Then Lcdout "0"
Lcdout #hours, ":"
hours = minutes Mod 60
If hours < 10 Then Lcdout "0"
Lcdout #hours, ":"
If seconds < 10 Then Lcdout "0"
Lcdout #seconds
Return

showvoltageonly:
'0V=0  2.5V=1023  2500/1023=2.444
voltage = (vfinal * 2) + (vfinal * 4 / 10)
voltage = voltage + (vfinal * 4 / 100) + (vfinal * 4 / 1000)
voltage1 = voltage / 1000
voltage2 = voltage Mod 1000
Lcdout #voltage1, "."
If voltage2 < 100 Then Lcdout "0"
If voltage2 < 10 Then Lcdout "0"
Lcdout #voltage2, "V"
Return

serialroutine:
UART_Write #vfinal, Lf
Return

endroutine:
address = address + 2
I2CWrite i2cdata, i2cclock, 0xa0, address, 255, 255
address = address - 2
Return

storeeeprom:
address = address + 2
I2CWrite i2cdata, i2cclock, 0xa0, address, vfinal.LB, vfinal.HB
Return

settime:
seconds = seconds + 5
If seconds >= 60 Then
	seconds = 0
	minutes = minutes + 1
Endif
Return

prog_memory:
finish = 0
While finish = 0
	Lcdcmdout LcdClear
	Lcdout "Memory Ready..."
	Gosub waitkey
	If key = c_left Then finish = 1
	If key = c_right Then
		For cnt = 2 To 20000 Step 2
			I2CRead i2cdata, i2cclock, 0xa0, cnt, sample.LB, sample.HB
			If sample = 65535 Then Goto exit2
			UART_Write #sample, Lf
		Next cnt
		exit2:
		address = cnt - 2
	Endif
Wend
Goto newprogram
Return

The schematics of the main board: view

The schematics of the power board: view

The photo of the prototype: view

20th Anniversary of theOSHONSOFT PROJECT(2001 - 2021)

Intelligent NiCd/NiMH Charger/Cycler with 2x16 Character LCD

20th Anniversary of the
OSHONSOFT PROJECT
(2001 - 2021)