RTC Calibration program
Posted: Tue Jul 16, 2019 2:46 pm
This program allows you to calculate the RTC calibration value to store in the \rtccalib.cfg file in your DM42's FAT drive.
Before running this program you'll first have to set the time correctly on your calculator and then wait a week or more to allow some drift to happen. The longer you wait to recalibrate, the more accurate the calibration will be.
When you run this program (XEQ "CALIB") you'll see a menu with four options. The three on the left, [DATE], [DRIFT] and [PREV] allow you to input data since the last calibration (or when the time was set if you've never calibrated), and [CALIB] on the right gives you the value to store in the calibration file.
1) Enter the date that the calculator's RTC was last calibrated (or set if you've not yet calibrated it) in the format normally used for dates, so that's dd.mmyyyy for me, 16.072019. Press [DATE]. The date you entered will be confirmed.
2) Enter the drift, in seconds, that has occurred since the date in 1). If the DM42 is running fast then the number of seconds is positive. If it's running slow then the drift is negative. Press [DRIFT] and the drift will be confirmed.
3) Enter the previous value you stored in rtccalib.cfg (or 0 if there is no rtccalib.cfg yet) and press [PREV]. That value will be confirmed.
4) Press [CALIB] and the (new) number to store in rtccalib.cfg will be displayed.
The .raw file is attached. The listing is as follows:
Before running this program you'll first have to set the time correctly on your calculator and then wait a week or more to allow some drift to happen. The longer you wait to recalibrate, the more accurate the calibration will be.
When you run this program (XEQ "CALIB") you'll see a menu with four options. The three on the left, [DATE], [DRIFT] and [PREV] allow you to input data since the last calibration (or when the time was set if you've never calibrated), and [CALIB] on the right gives you the value to store in the calibration file.
1) Enter the date that the calculator's RTC was last calibrated (or set if you've not yet calibrated it) in the format normally used for dates, so that's dd.mmyyyy for me, 16.072019. Press [DATE]. The date you entered will be confirmed.
2) Enter the drift, in seconds, that has occurred since the date in 1). If the DM42 is running fast then the number of seconds is positive. If it's running slow then the drift is negative. Press [DRIFT] and the drift will be confirmed.
3) Enter the previous value you stored in rtccalib.cfg (or 0 if there is no rtccalib.cfg yet) and press [PREV]. That value will be confirmed.
4) Press [CALIB] and the (new) number to store in rtccalib.cfg will be displayed.
The .raw file is attached. The listing is as follows:
Code: Select all
00 { 191-Byte Prgm }
01▸LBL "CALIB"
02 FIX 06
03▸LBL 00
04 CF 22
05 CLMENU
06 "DATE"
07 KEY 1 GTO 01
08 "DRIFT"
09 KEY 2 GTO 02
10 "PREV"
11 KEY 3 GTO 03
12 "CALIB"
13 KEY 6 GTO 06
14 MENU
15 STOP
16 GTO 00
17▸LBL 01
18 FS?C 22
19 LSTO "DATE"
20 VIEW "DATE"
21 GTO 00
22▸LBL 02
23 FS?C 22
24 LSTO "DRIFT"
25 VIEW "DRIFT"
26 GTO 00
27▸LBL 03
28 FS?C 22
29 LSTO "PREV"
30 VIEW "PREV"
31 GTO 00
32▸LBL 06
33 RCL "DATE"
34 DATE
35 DDAYS
36 0.0864
37 ×
38 RCL "DRIFT"
39 X<>Y
40 ÷
41 2
42 ENTER
43 20
44 Y^X
45 X<>Y
46 ×
47 LASTX
48 1ᴇ6
49 +
50 ÷
51 +/-
52 ENTER
53 SIGN
54 0.5
55 ×
56 +
57 IP
58 RCL+ "PREV"
59 "rtccalib.cfg="
60 AIP
61 AVIEW
62 GTO 00
63 END