| Features |
K145 |
VK011
|
K190
|
| Visuals |
 |
|
|
| Source |
DIY/Kitsrus
(through its distributors) |
QKits |
DIY/Kitsrus
(through its distributors) |
Based
on |
Quozl |
Unknown |
New
design by Frank Crivelli, inspired by K145. |
| Temperature
Sensors |
DS18S20
1-Wire |
DS18S20
1-Wire |
DS18S20
and DS18B20
1-Wire (can be mixed) |
| #
of Channels |
4 -
temperature monitoring only. |
4 -
temperature monitoring only. |
4 of
temperature monitoring
and 4 of relay control. |
|
Communications |
Serial
2400/8/N/1 |
Serial
9600/8/N/1 |
Serial
9600/8/N/1
or 2400/8/N/1 |
|
Full RS232 |
No |
No |
Yes |
|
Power source |
From the serial port |
From
the serial
port,
or external (by jumper) |
12V
DC external |
|
Power indicator |
No |
Yes |
Yes |
|
Data indicator |
No |
No |
Yes |
|
Configurable |
F/C jumper on board only
**There is apparently a calculation error when using
Deg F,
at temperatures above
95 Deg F.
See Quozl's
Wiki
|
Yes,
internal config, accessible from external device (eg:
PC). Set F or C, or both; Data in tab or csv
format; Data rate adjust from 1 per second to 1 per 99
minutes; View 1-wire device serial #s, crc errors, Hi/Lo
values, and connection problems for each sensor connected. |
Baud
rate jumper on the circuit board. |
|
Data send |
Automatically sends 1 channel per
second. So, 4 channels will take 4 seconds. |
Automatically sends 4 channels one after the other, but in a
"burst". Frequency of bursts is dependent on
configured data rate. |
The
board has to be polled (send a command) to get temperature data. |
|
Control data send (on/off) |
Indirectly, through the DTR
line,
which is the power supply line. |
As
wired, no -- it starts sending as soon as a connection is established.
Could be rewired to be similar to K145. |
Yes
- send a command to get data. |
|
Live sensor connect/disconnect |
Yes |
Yes |
Yes |
|
On-board transient protection |
No |
No |
No |
|
Reset function |
No, disconnect/reconnect (ie:
remove power) to force a reset. |
As
for K145. |
As
for K145. |
|
Board can be mounted in
a case. |
Yes, but modifications needed. |
As
for K145. |
Case
is included. |
|
Software included |
No |
No |
Yes |
|
Cost (at Jan/09) |
$28.95 USD at QKits |
$29.95
USD at QKits |
$76.95
USD at QKits |
|
|
|
|
|
Notes
1. It's not difficult to add an LED to the K145 for power indication (see here).
2. The F/C jumper on the K145 board isn't too useful -- it's more efficient to set the board
to Deg C, and do the Deg F conversion in software.
3. As with the K145, the VK011 internal config features are mostly not useful. The
exception might be checking for crc errors or device serial numbers, or viewing
connection status. Otherwise, the available config features are better done in
software.
4. From looking at how communication works for accessing the internal config features
of the VK011, it appears the VK011 board was originally designed to connect to
something other than a PC. Most likely another microcontroller board, with timestamp
capabilities, a keypad, an LCD display, and EEProm storage. This could make for a
"portable" solution, and fits with the reference in the VK011 docs to the possibility of
using solar power. The internal config features make more sense when the board is
used in this way.
5. QKits also have a "polling" version of the VK011 (# VK011P). With this version, the
software tells the board when to send data. This is the opposite of the standard
version, which is constantly sending data.
6. As noted in the chart, the K190 has to be polled to get temperature data. Thermostat
(relay) control is done through the computer software. The command structure for
getting data or controlling relays is similar to that of the K108 relay board. Commands
are in a simple text format. Temperature data can be taken from individual channels,
or all 4 channels together.
7. There is a K190 firmware upgrade (K190E) available from Ozitronics. It has internal
thermostat settings, so it can be disconnected from the computer, and still maintain
temperature control. Temperature data is pushed out to the computer (like K145)
rather than being polled. The push rate is configurable. There is also a relay "Toggle"
command added to the command set. Thermostat and push rate config settings are
saved internally in the new firmware.
8. See this page for a comparison of
software versions for the K190.
9. MinTermLite is useful for testing connections
and commands with these kits. |
