Carrier boards

In addition to customer-specific carrier boards, standard carrier boards from Loetronic can also be used. It is then possible to connect loudspeakers or headphones directly and they fit into Loetronic’s standard housings. In addition to the use of the MP3 modules as an embedded module, ready-made MP3 players can also be supplied in functional housings. The serial interfaces of the ULTRA MP3 module are expanded on the carrier boards by appropriate standardised interfaces, including USB, RS232 / RS485 or LAN.

 
Figure 3: The mother / carrier board allows the MP3 Module to be built into Loetronic’s standard enclosure

ULTRA MP3 Module for a checkout lane system

Last but not least, this article briefly describes a system in which the ULTRA MP3 module plays an important role and Loetronic, a decisive role. Back in 2011, Rickert Systemtechnik asked Loetronic to integrate an audio module into a so-called till lane (checkout lane) opening system. The company Rickert Systemtechnik has specialized in these systems and equips warehouses with it. These systems ensure that the customer flows to the checkout desks in a targeted way, and are primarily intended to prevent the developing of queues at the cash desks. In addition to visual possibilities at the cash desks and the store, only simple bells and chimes were used in the past. The use of the ULTRA MP3 module in such a system opened many new possibilities. Now new opened check stations could also be made audible, the Store Manager could be called to the checkouts, or employees to the bakery area or bottle deposit machines.

In addition to the use of the ULTRA MP3 module in existing checkout lane opening systems, Rickert Systemtechnik was also interested in the further development of its systems and Loetronic was the ideal partner for this development. Since 2011 the checkout lane opening systems have been further developed, perfected and manufactured in various versions.

The overall complexity of the cash register system has grown over the past few years and shows the growing know-how of Loetronic in the microcontroller and interface area. A number of customer projects have already been implemented in a similar manner, which have proved themselves over many years.
 
Essential technical components of a checkout lane system in terms of microcontroller and interface technology used
The centrepiece of the checkout lane opening system is a central control unit, which also accommodates the ULTRA MP3 module, monitors all processes at the cash desks and informs the customers and employees of all statuses audiovisually. Via so-called tableau units at the cash desks the employees can log on and off their own or other checkouts and select other functions. Corresponding lamps, mostly LED-based, display their status at the cash desks. Additional peripheral devices or systems can be connected to the system via additional interfaces, e.g. bakery product dispensers and bottle deposit machines, sensors for automatic customer recognition at the cahier stations or certain sales areas, as well as monitors for further visualization of sales information.
The central controller unit, like the ULTRA MP3 module, is based on a 16-bit microcontroller from Freescale (NXP). Via a serial interface, it communicates with the MP3 module and initiates voice announcements. A second serial interface is used to communicate via a proprietary RS485 bus. This bus interface was developed in close collaboration with Rickert Systemtechnik in order to be able to connect its own interface extensions even over a great distance to the system. In addition, it is also possible to interconnect several central controller units via the RS485 bus, in order to connect multiple cash registers. A third serial interface of the microcontroller can be connected to a LAN module (Lantronix XPort) to enable the controller unit to have a direct LAN interface. A USB interface was connected via an FTDI chip via I2C.
The LED lamps are either directly controlled by the microcontroller or via port expansion modules in the case of insufficient digital outputs.
The tableau units themselves are not controlled via a bus interface, but via an SPI interface with RS232 level. Due to the RS232 level, as well as the RS485 interface, considerable distances can be bridged, and a variable number of input and output signals can be queried and adjusted by the selection of the SPI interface. This is important in this respect as different tableau units can be used at the cash desks, and depending on the stores, different cash desks must be controlled by a tableau unit. Besides the use of buttons on this unit, other external signals can also be addressed through this unit. The outputs to the panel unit control LEDs on the panel or other cash-related external devices.
Furthermore, an optional RTC module can be installed on the controller unit in order to play timely precise announcements. The complexity of the controller unit makes it necessary to adapt the internal firmware to the respective environment via configuration parameters. In order to enable the customer to do this simply and quickly, Loetronic has programmed Windows software which communicates via the USB interface of the controller and also allows the installation of new firmware.